Introduction

The normal high amount of interest and excitement has surrounded the release of Dell's new 2013 line-up of UltraSharp screens, with the announcement late in 2012 that we would see a new 24" U2413 and a new 27" U2713H model released. These new displays are designed to replace some of their older models and we thought it would be useful to go into a little bit of detail about the evolution of the Dell UltraSharp range at this time.

Dell's UltraSharp naming scheme can be a little confusing to new users and there's now a few models with quite similar names, but with very different specs and features.

24" UltraSharp - The U2410 was released in 2009 and was the first of the 24" range to use the new "U" prefix and a move to the popular IPS panel technology. The screen was aimed primarily at higher end users and offered a range of features and specs which separated it from more mainstream models. It featured a wide colour gamut thanks to its WCG-CCFL backlight unit, 10-bit colour depth (8-bit + FRC producing 1.07 billion colours), factory calibration, a 12-bit LUT (not programmable unfortunately), touch-sensitive buttons, and a large range of connections, adjustments and extras. In 2011 Dell released the U2412M, with the M reportedly representing the use of a more standard colour depth (16.7m colours). In the case of the U2412M this was a 6-bit + FRC panel. It was aimed more at mainstream users with a lower retail cost and a more "friendly" standard gamut which is more suitable for the more casual user. It represented the move to the popular W-LED backlighting technology as well, bring about energy and environmental benefits. This U2412M was released to run along side the U2410, giving users the option to choose which was more suited to their requirements and budget. Now at the beginning of 2013 we are about to see the arrival of the U2413. Note the absence of the "M" at the end, as this is again a return to the higher end specs of the U2410 (8-bit + FRC panel = 1.07b colours). In fact the U2413 is designed to replace the U2410 and many of the specs and features are similar to that older screen. It too has a wide gamut, now thanks to the new generation of GB-LED backlighting instead of older CCFL units. It again features a 14-bit LUT, this time programmable by the user with the right hardware. Factory calibration has returned, as has the card reader and touch-sensitive buttons. A few other high end features have also been included this time including a uniformity compensation technology, USB 3.0 and a wider range of options for things like aspect ratio control. The U2413 represents a replacement for the U2410 with some fancy new upgrades, but Dell will continue to sell this new model alongside the existing U2412M which may still be more suitable (and accessible) for many mainstream users.

27" UltraSharp - in 2010 Dell also released their first U prefix UltraSharp screen, the U2711. The pattern is very similar to the 24" models. This original U2711 offered the high end specs and features for the more demanding professional users, including 10-bit colour support (8-bit + FRC = 1.07b colours), factory calibration, wide gamut CCFL backlighting etc. Later on in 2012 Dell released the U2713HM to run along side the existing U2711. Like with the 24" models, this represented a move to W-LED backlighting, a standard colour gamut and 8-bit colour depth (note the "M" again at the end signifying a normal 16.7m colour depth). Dell also dropped a few of the extras like the card reader, touch-sensitive buttons and extended internal LUT. You may also note the addition of an "H" at the end of the model number here, which is now used by Dell to signify 16:9 aspect ratio screens. Of course the U2711 was also 16:9 aspect ratio (both are 2560 x 1440 resolution) but at the time they did not use this H in their naming scheme. Now, right at the end of 2012, Dell have released a new model, the U2713H (reviewed here!). This retains the H to signify the 16:9 aspect ratio again but there is no "M" this time, as Dell have moved back to the higher end specs of the original U2711. Like with the U2413 and U2410, this new model will replace the U2711. It features a 1.07b colour depth, wide gamut (GB-LED backlighting), 14-bit programmable LUT and a range of other new features to match those we've discussed with the U2413 above.

So to summarise, soon Dell will be stopping production of the U2410 and U2711 as they will now be replaced by the U2413 and U2713H respectively. These will be available along side the other recent models, the U2412M and U2713HM with the distinction being made based on specs and features. The U2413 / U2713H will be aimed more at professional users and more demanding requirements, while the U2412M and U2713HM will be more mainstream and probably more suited for an average user in most cases.

Specifications and Features

The following table gives detailed information about the specs of the screen:

Manufacturers website link: Dell

The U2713H offers a very good range of video connections which is great to see and something which Dell have always done a good job with on their UltraSharp models. There are HDMI, Dual-link DVI-D, DisplayPort and now Mini DisplayPort provided for video interfaces. The D-sub connection which was available on older screens including the U2713HM has now been left off, presumably because it's less commonly used and cannot support the full native resolution of the screen anyway. It's nice to see HDMI provided for users who want to connect other devices, particularly external Blu-ray and DVD players. The digital interfaces are HDCP certified for encrypted content as well. There is also an audio out connection for connecting headphones / external speakers if you wish to take the sound from the HDMI or DisplayPort inputs. There are no integrated stereo speakers on this model although the screen is compatible with Dell's SoundBar if you wish.

The screen comes packaged with a dual-link DVI and DisplayPort >  Mini DisplayPort cables which is useful although there is no normal DisplayPort or HDMI cable provided with the screen unfortunately, presumably due to cost saving measures. The screen has an internal power supply and so you only need a standard kettle lead (provided) to power the screen. There is a 4-port USB 3.0 hub provided as well, with 2 ports on the back and 2 ports on the left hand side of the screen. The USB cable to connect back to your PC to power these ports is provided in the box. Like the older U2711 model there is a card reader on this model (9-in-1) which was something left off the U2713HM but which personally I find useful. A nice extra.

As we've already discussed in the introduction the screen features a programmable 14-bit LUT to allow for hardware level calibration via the appropriate software/hardware (see hardware calibration section later on for details). The screen also has a uniformity correction technology which we will test later on as well.

Below is a summary of the features and connections of the screen:

OSD Menu

Above: views of OSD operational buttons

Like the U2711, the Dell U2713H has touch-sensitive OSD buttons. These were done away with for the U2713HM model, but have been brought back here for that extra "premium" feel". These 5 buttons are located on the right hand side of the screen next to a pressable power button. The sensitivity works well in practice. Hovering your finger over any of them lights up the bottom button. If you then press that bottom button it brings up the 5 options available from the 5 touch sensitive buttons as shown below. All the buttons then light up in a white colour to show they are now available to use. The power LED glows white by the way during normal use, and pulses on / off white when the screen is in standby.

From here there is quick access to preset mode selection, brightness / contrast controls and the input source. One more option than was available from the U2713HM which is useful. You can also select to enter into the main menu, or simply exit the quick launch menu. You can in fact personalise the three quick launch options from within the main menu should you wish to.

  

Within the preset modes menu there are options for standard, multimedia, movie, game, paper, colour temperature, color spaces and custom colour. The paper preset is new and replaces the 'text' mode which used to feature instead on Dell monitors like this. The color space mode is also a new one, giving you access to the sRGB and Adobe RGB emulation modes as well as 2 user calibrated modes if you hardware calibrate the screen (above left). The sRGB and Adobe RGB modes here also carry the factory calibration which we will test later on. If you enter the 'custom color' mode you have access to adjustments for gain, offset, hue and saturation (above right), giving the user a great control over the hardware.

The input source quick launch gives you access to the video inputs as above, which includes a handy "scan sources" option which wasn't available on the U2713HM.

The brightness/contrast quick launch gives you access to those controls as shown above.

Bringing up the main menu presents you with various sub-sections down the left hand side as shown. Please ignore the fact these screenshots show the Dell U2413 name at the top as the same menu software is used on the U2713H anyway, and these were the images provided in the Dell user manual. The OSD menu is actually a little bit taller than this but the options and controls remain the same. Obviously the bottom would confirm the appropriate resolution being used, in our case the native 2560 x 1440 at 60Hz.

At the top right there is the now familiar "energy use" bar which gives you a visual indication of the power consumption at any given time. This is based on the OSD brightness setting which controls the backlight intensity, and therefore has a direct correlation to the power consumption. The brightness/contrast section is self explanatory of course and is shown above.

The input source section allows you to manually select which interface is in use.

Colour settings allows you to change a couple of settings relating to colour format and gamma, but perhaps more useful here is access to the preset colour modes.

The preset modes listed here are the same as those accessed via the quick launch menu.

 

The display settings section allows you to change the monitors aspect ratio for external devices and games. There are options for wide 16:9, auto resize, 4:3 and 1:1 here. Ignore the "16:10" in the screenshot above as that relates to the Dell U2413. You can also turn the dynamic contrast ratio control on and off in this section of the menu, if you are in a suitable preset mode where it can be activated. Of other note is the new 'Uniformity Compensation' option which we will test later on as well. There is also a new 'Smart Video Enhance' feature and an option to set up the DisplayPort daisy chaining.

The PiP settings section allows you to control various options related to Picture In Picture (PiP) and Picture By Picture (PbP). The following configurations are available according to the manual.

 

The other settings section has some controls over the OSD itself. The 'Energy Smart' feature can be turned on and off here as well.

The personalize section allows you to change the quick launch keys if you wish. You can change them to activate preset modes, brightness/contrast, input source, aspect ratio and PiP mode if you wish.

Overall the OSD menu offers a decent range of options and it is intuitive and well structured. The touch sensitive buttons worked well on the most part although we did find it a little tricky to click and hold a button sometimes (e.g. when scrolling rapidly between brightness settings). Sometimes they didn't respond as hoped but on the whole they were useable.

 

Power Consumption

In terms of power consumption the manufacturers spec states typical usage of 60W and 130W maximum (with luminance max, USB connected and SoundBar connected). In standby the screen apparently uses <0.5W.

We tested this ourselves and found that out of the box the screen used 59.8W of power while at its default brightness setting. At the maximum brightness level the screen used 66.8W of power, and at the lowest setting this was measured at 28.4W. Once calibrated we had reached a power consumption of 41.4W which had been once the screen had been set to achieve a luminance of 120 cd/m². During standby the screen uses 1.3W of power. I have plotted the results of these measurements on the graph below:

 

Panel and Backlighting

Panel and Colour Depth

The Dell U2713H utilises an LG.Display LM270WQ3-SLA1 AH-IPS panel which is capable of producing 1.07 billion colours with an 8-bit colour depth and additional Frame Rate Control (FRC) stage (8-bit + FRC). Dell refer to the panel as being "AH-IPS" (Advanced High Performance IPS) in some of their marketing material, and it is a name which is starting to become more common in today's IPS market. We have started to see other screens emerge with these so-called AH-IPS panels in their specs, and indeed LG.Display themselves made the same distinction when discussing their forthcoming panels (including this one) earlier in the year. This new Q3 panel actually does represent a new generation of IPS in so much as it features a new type of backlighting which we will discuss in a moment.

The panel is confirmed when dismantling the screen as shown below.

Above: view of the panel used and dismantled screen.
 

Like the U2711 which it is replacing, the new U2713H offers support for 10-bit content through the use of its 8-bit + FRC panel. This gives a colour depth support for 1.07 billion colours. However,  you need to take into account whether this is practically useable and whether you're ever going to truly use that colour depth. You need to have a full 10-bit end to end workflow to take advantage of it which is still quite expensive to achieve and rare in the market, certainly for your average user. This includes relevant applications and graphics cards as well, so to many people this 10-bit support might be irrelevant. Given the U2713H's position as a professional grade, high-end screen, it's pleasing to see the support included. The U2713HM for reference offered a standard 8-bit colour depth (16.7m colours).
 

Panel Coating

The screen coating on the U2713H is much like that featured on the U2713HM which had been a positive change at the time. It is a normal anti-glare (AG) offering as opposed to any kind of glossy coating. However, this is contrary to a lot of other older IPS based screens which usually feature a grainy and aggressive solution. In fact the Dell U2711 featured such a coating and was often criticized for its grainy, dirty appearance, especially on light coloured backgrounds. When Dell released the U2713HM users were impressed by the new lighter AG coating which is an almost semi-glossy type coating. This has been retained on the new U2713H as well thankfully. Dell seem to have toned down the AG coating on recent models which is great news. It retains its anti-glare properties to avoid unwanted reflections, but does not produce an overly grainy or dirty image that some AG coatings can.

As a side note, some users reported a "cross hatching" appearance on the original U2713HM screen, where on very close inspection you could detect a small grid like effect as part of the coating. This didn't affect everyone of course but it was something some people complained about or became sensitive to. Having seen this so-called cross hatching on the U2713HM we're pleased to report that the U2713H is free from this and does not show any sign of it, even when looking very closely for it.
 

Backlighting and Colour Gamut

The U2713H uses a new form of backlighting which we haven't seen before. The old U2711 model featured a CCFL backlight unit which supported a wide colour gamut (WCG-CCFL). When Dell released the U2713HM they moved to the very popular and widely used W-LED (White-LED) backlighting which offers environmental and energy benefits along with a thinner form factor. This delivered a normal sRGB colour space only, but was more suitable for most general users. With the new U2713H Dell wanted to be able to offer the benefits of LED backlighting but deliver a wide colour gamut support for colour critical work and the professional users. With the new LG.Display LM270WQ3 panel they have moved to a new GB-LED backlight system.

Above: GB-LED backlight spectrum, courtesy of PCmonitors.info

The common White-LED backlight systems, despite their name, do not actually use White LED's, but rather they emit a blue light which passes through a yellow phosphor to give a more neutral white and provide the red and green components of the image. With the new GB-LED backlights, rather than using this blue diode + yellow phosphor, the backlights combine green and blue diodes with a red phosphor (i.e. Green-Blue LED = GB-LED). PCMonitors.info has a useful article about The Evolution of LED Backlights which is well worth a read as well. With this new type of LED backlight the screen covers 103% of the NTSC reference, 99% of the Adobe RGB reference and 100% (and beyond) of the sRGB space. The screen is of course classified as a wide gamut display and the colour space coverage is actually ever so slightly more than the old U2711 with a WCG-CCFL unit (which has 102% NTSC and 98% Adobe RGB coverage). We expect to see this type of backlight adopted more widely during 2013.
 

PWM Flicker Tests at Various Backlight Brightness Settings - Updated 30 July 13

100%                                                     50%                                                    0%

We tested the screen to establish the methods used to control backlight dimming. Our recent article talks in more details about a common method used for this which is called Pulse Width Modulation (PWM). A series of photos was taken using the method outlined in the article. These were taken at maximum 100%, medium 50% and minimum 0% brightness settings. These tests allow us to establish 1) whether PWM is being used to control the backlight, 2) the approximate frequency at which this operates, and 3) whether a flicker may be introduced or potentially noticeable at certain settings.

A thin white line was shown on an all-black background and a photograph was taken at a slow shutter speed of 1/8 second (in this example) as the camera was scanned left to right in front of the screen. This produces a series of white lines which can be used to identify the frequency of the PWM and how quickly the backlight is cycled on and off. The higher this frequency, the less likely you are to see artefacts and flicker. The duty cycle (the time for which the backlight is on) is also important and the shorter the duty cycle, the more potential there is that you may see flicker. Please remember that not every user would notice a flicker from the backlight but it is something to be wary of. It is also a hard thing to quantify as it is very subjective when talking about whether a user may or may not experience the side effects. We are able to at least measure the frequency of the backlight using this method and tell you whether the duty cycle is sufficiently short at certain settings that it may introduce a flicker to those sensitive to it.

From these tests we can confirm that the U2713H does not use PWM at all for dimming of the backlight, which is the same as the U2713HM in fact. Even at 0% brightness there was no sign of the usual splitting of the white line that you'd expect to see in these tests. We carried out the checks at an even slower shutter speed which returned the same result. This is great news for those who are affected by flickering backlights and suffer from eye fatigue and eye strain. It seems we have seen quite a few new monitors recently which don't use PWM for backlight dimming including other 27" models like the DGM IPS-2701WPH, ViewSonic VP2770-LED and Dell U2713HM. Some subsequent tests using an oscilloscope revealed some overlapping oscillation at lower brightness settings of between 50 - 20%. This was a very high 11,250Hz and with a low amplitude and so should still not produce any visible flicker.

 

Testing Methodology

An important thing to consider for most users is how a screen will perform out of the box and with some basic manual adjustments. Since most users won't have access to hardware colorimeter tools, it is important to understand how the screen is going to perform in terms of colour accuracy for the average user.

I restored my graphics card to default settings and disabled any previously active ICC profiles and gamma corrections. The screen was tested at default factory settings using the DVI interface, and analysed using an X-rite i1 Pro Spectrophotometer (not to be confused with the new i1 Display Pro colorimeter) combined with LaCie's Blue Eye Pro software suite. An NEC branded and customised X-rite i1 Display 2 colorimeter was also used to verify the black point and contrast ratio since the i1 Pro is less reliable at the darker end.

Targets for these tests are as follows:

• CIE Diagram - validates the colour space covered by the monitors backlighting in a 2D view, with the black triangle representing the displays gamut, and other reference colour spaces shown for comparison

• Gamma - we aim for 2.2 which is the default for computer monitors

• Colour temperature / white point - we aim for 6500k which is the temperature of daylight

• Luminance - we aim for 120 cd/m², which is the recommended luminance for LCD monitors in normal lighting conditions

• Black depth - we aim for as low as possible to maximise shadow detail and to offer us the best contrast ratio

• Contrast ratio - we aim for as high as possible. Any dynamic contrast ratio controls are turned off here if present

• dE average / maximum - as low as possible. If DeltaE >3, the color displayed is significantly different from the theoretical one, meaning that the difference will be perceptible to the viewer. If DeltaE <2, LaCie considers the calibration a success; there remains a slight difference, but it is barely undetectable. If DeltaE < 1, the color fidelity is excellent.

Default Performance and Setup

Default settings of the screen were as follows:

Dell U2713H - Default Factory Settings, Standard Mode

 

 

The screen comes out of the box in the 'standard' preset mode, although there are additional preset modes which carry a factory calibration which we will test shortly. Default setup of the screen felt too bright which is pretty standard for modern screens but can be easily controlled of course via the brightness control. You could immediately spot the use of the wide gamut GB-LED backlight as well, with colours looking more saturated and vivid than a normal standard gamut screen. Reds and greens in particular looked more vivid and more exaggerated. This is common for wide gamut screens of course. Some people actually prefer the more saturated colours for things like gaming and movies, even if it's at the cost of accuracy. We will look at the sRGB emulation mode in a moment which is also provided to avoid complications outside of colour managed applications for those wanting to work specifically in the sRGB colour space and on a standard gamut screen.

 

Out of the box the performance of the screen was not great in this standard mode, and we were hopeful of better performance from the factory calibrated modes. The CIE diagram on the left of the image confirms that the monitors colour gamut (black triangle) extends considerably beyond the sRGB colour space (orange triangle), especially in green shades. This is representative of the screens wide gamut and 103% NTSC colour space coverage.

 

 

We have also provided a comparison of the screen against the wider Adobe RGB reference in this standard preset mode, where the full native gamut of the backlight is used. You can see that it extends beyond the Adobe RGB reference as well in some greens and reds, but does fall slightly short in the green spectrum, giving rise to the quoted 99% Adobe RGB coverage. We will test if the Adobe RGB space can be more closely matched using the defined Adobe RGB mode in a moment as well.

 

 

Default gamma was recorded at 2.5 average, leaving it a high 15% out from the target of 2.2 which was a little disappointing. In darker grey shades the gamma was closer to 2.2, but it deviated all the way up to 2.56 in lighter grey shades. White point was a little off the target as well, being a little too warm and recorded at 6091k (6% out). Note that we are using a spectrophotometer to make these measurements which is not sensitive to the LED backlight as some colorimeter devices can be. When using a standard gamut colorimeter not designed to work with modern backlighting units like W-LED, WCG-CCFL and GB-LED there can be a typical deviance of 300 - 600k in the white point measurement which is why some sources may refer to a different white point in this test incorrectly.

 

Luminance was recorded at a high, but not too bright 252 cd/m² which is still too high for prolonged general use. The screen was set at a default 50% brightness in the OSD menu but that is easy to change of course to reach a more comfortable setting. The black depth was a good 0.30 cd/m², giving us a pretty good static contrast ratio of 845:1. This was good for an IPS panel and a fairly similar performance to what we had seen from the U2713HM in fact (910:1). Colour accuracy was poor in this measurement but this is a result of the monitors native gamut, being much wider than the reference sRGB. DeltaE was recorded at 4.8 average, with maximum of 10.7. Testing the screen with various gradients showed smooth transitions with no sign of any banding thankfully. The usual slight gradation was evident in darker tones as you will see from most monitors.

 

 

 

 

Dell U2713H - Default Settings, Custom Color Mode

   

 

We also tested the default performance in the 'custom color' preset. This mode allows you access to the individual RGB channels which will give you more control over the hardware when it comes to calibration. The performance in this mode was similar overall to the 'standard' preset. As you switched to this mode you did see a step up in the luminance of the display which was confirmed with a measurement of 301 cd/m² brightness. The contrast ratio was a little higher in this mode at 1008:1 since the RGB channels were now all at 100% by default (in standard mode these are preset at defined, fixed lower levels to reach the white point of that mode).

 

 

The gamma remained at a similar 16% deviance with 2.6 average, and white point was now a little warmer still than before being 8% out but measured at 5990k. This mode seemed slightly worse in terms of gamma and white point than the standard mode, but would at least allow the user to tweak things themselves to help correct things. Colour accuracy remained poor because of the comparison of the monitors native gamut with the sRGB reference. DeltaE was 4.0 average / 9.0 dE maximum.

 

 

 

Factory Calibration

 

 

Like its predecessors (U2711 and U2713HM) the Dell U2713H comes factory calibrated to some extent, and the box even includes a calibration report from Dell specific to the unit you have. It states that every unit is shipped incorporating pre-tuned sRGB and Adobe RGB modes which offers an average DeltaE of <2. This is better than on the U2713HM in fact which only featured a factory calibrated sRGB mode (since it was a standard gamut screen) with dE < 5. In addition to this, they have tweaked gamma and grey-scale to help to ensure smooth gradients and an accurate initial setup. As a new extra they have also apparently adjusted luminance and colour uniformity across the screen which is available from within the OSD as an option we will test later on. I've included a copy of the calibration report from the Dell factory below for you to review. Note that this report is only relevant to our specific test unit and they do state that results may vary with each setup and different test equipment.

 

I was interested to see if this factory calibration helped at all with default settings. Note that this is only relevant for the sRGB and Adobe RGB preset modes available through the OSD menu. You will need to change from the default 'Standard' profile to benefit from these factory calibrated settings.
 

Dell U2713H - Default Factory Calibration, Adobe RGB mode

   

 

The factory calibration of the Adobe RGB preset mode was pleasing on the most part. This mode actually offered a reliable emulation of the Adobe RGB colour space as well, helping to cut back the slight oversaturation of the screens native colour space and now very closely matching the Adobe RGB reference. If you prefer this to the full native gamut of the screen it might be useful for colour critical work in this colour space.

 

Comparison of Adobe RGB colour space coverage in Standard preset mode (native gamut - left) and in Adobe RGB emulation mode (right)
 

 

 

 

The average gamma was much better than the default standard mode which had given us a 2.5 gamma average and resulting 15% deviance from our 2.2 target. Here it was improved a fair amount but remained 5% out from the target at 2.3 average. White point was also now closer to the 6500k target, and was measured at 6416k (1% out). You may note that the factory calibration report shown above which was included with the screen shows that the factory calibration was in fact aiming for 6000k grey-scale, and not 6500k. It seems that this is a little out but a pleasing side-effect of this is that it is actually closer to the 6500k target we wanted anyway.

 

Luminance was still too high and this was perhaps the main area which deviated from our target. A simple OSD brightness change can of course overcome this though so this is no big issue. Contrast ratio remained similar to the standard preset mode at 810:1. Colour accuracy (as compared with sRGB) was still off in this measurement due to the wide gamut of the screen, with a dE average of 4.7 and maximum of 9.6. This mode did offer a good factory calibration in terms of white point and gamma and a reliable emulation of the Adobe RGB colour space as well.

 

Dell U2713H - Default Factory Calibration, sRGB mode

   

 

The factory calibration of the sRGB preset mode was also pleasing on the most part. This mode offered a reliable emulation of the sRGB colour space, helping to cut back the large oversaturation of the screens native colour space and now very closely matching the sRGB reference. This might be useful for colour critical work in the sRGB colour space and also for those who want to avoid complications with wide gamut and colour management, not to mention with movies and games.

 

 

The gamma was still a little out from the target of 2.2, being measured at 2.4 average (7% deviance). This was an improvement over the default standard preset mode though. The white point was again better than the default mode, now being measured at 6260k (4% out). Luminance was still too high, but easy enough to adjust through the OSD menu. The contrast ratio was very similar to before as well at 800:1. Since we are now working with an sRGB colour space the colour accuracy tests are more useful since they are based on an sRGB reference. The dE average was 1.5 and maximum was only 3.2. This represented a good accuracy from the factory calibration. We would have liked a slightly more accurate gamma and white point setup in this mode, but the emulation of the smaller colour space and the accuracy of the colours was pleasing.

 

 

 

Testing Colour Temperatures

 

 

The U2713H features a range of colour temperature presets within the OSD 'color settings' menu as shown above. You have to choose the specific 'color temp' preset mode first but you are then asked to define your target colour temp from the 6 presets available. We measured the screen with the X-rite i1 Pro spectrophotometer in each of the preset modes to establish their colour temperature / white point. All other settings were left at factory defaults and no ICC profile was active. The results are recorded below:

 

 

 

 

The colour temperature modes offered reasonable levels of accuracy overall with a maximum deviance from the target of only 7.2%. The coolest settings of 10,000k and 9300k seemed to be the closest to the target as a measurement with 73 - 225k difference from the desired settings (0.8 - 2.3% deviance). The 7500k mode was pretty close to the target but the warmer settings of 6500k and below deviated a little more, ranging up to 5.5% deviance at 6500k, and up to 7.5% deviance at 5000k setting. Overall the preset colour temp modes were reasonable really although not as accurate as you might see on some other high end pro grade screens from the likes of Samsung, NEC and Eizo.

 

 

 

Software Calibration Results

 

The U2713H may well have a decent factory setup in some modes but given the market for this screen I expect many users will want to calibrate the screen personally to obtain even higher levels of accuracy and allow profiling and matching between different devices.  Remember, you need to ensure you have a device capable of measuring and reading the spectra from the GB-LED backlight unit properly. Many older colorimeter devices are designed to work with standard gamut CCFL units only and so they can often have difficulty reading LED (and wide gamut CCFL) units properly. A spectrophotometer does not have this problem and there are also some decent modern colorimeters like the X-rite i1 Display Pro which should be able to read LED without issue. While you can use other devices and various software packages to complete software profiling of the screen, you may come across issues if the device is not designed to work with an LED backlight unit.

 

The U2713H also offers hardware calibration which can give you very high levels of accuracy and control over the monitors 14-bit LUT itself. We will look at that in a moment, but we also wanted to carry out the usual software level "calibrations" (profiling) at a graphics card level. We used the X-rite i1 Pro spectrophotometer combined with the LaCie Blue Eye Pro software package to achieve these results and reports. An NEC branded and customised X-rite i1 Display 2 was used to validate the black depth and contrast ratios due to lower end limitations of the i1 Pro device.

 

 

Dell U2713H - Calibrated Settings, Custom Color Mode

   

 

I first of all reverted to the 'custom color' mode in the preset section of the OSD menu which would allow me access to the individual RGB channels. There is actually a very wide range of controls here if you need them for gain, offset, hue and saturation, allowing the user to make finite adjustments where necessary. Adjustments were made during the process to the brightness control, and to the RGB channels as shown in the table above. This allowed me to obtain an optimum hardware starting point and setup before software level changes would be made at the graphics card level which would help preserve tonal values. After this I let the software carry out the LUT adjustments and create an ICC profile.

 

 

Average gamma had been corrected to 2.2 with 0% deviance according to the initial test correcting the large default 16% deviance we'd found in this preset. Checking the more detailed table shown above, the gamma was slightly too high in the darker grey tones, and slightly too low in the lighter tones. The 8% deviance in the white point from our target of 6500k had also been corrected here and the colour temperature was now pretty much spot on at 6516k. Luminance had also been corrected thanks to the adjustment to the brightness control, now being measured at 120 cd/m² spot on. This also gave us a calibrated black depth of 0.16 cd/m², and a static contrast ratio of 800:1 which was pretty good for an IPS panel. Colour accuracy had also been corrected nicely, with dE average of 0.4 and maximum of 1.2. LaCie would consider colour fidelity to be excellent.

 

Testing the screen with various colour gradients showed mostly very smooth transitions. There was some slight gradation in darker tones and some very slight banding introduced due to the adjustments to the graphics card LUT from the profilation of the screen. Nothing major at all though. It's worth also commenting on the screen coating in this section of the review. Unlike many other IPS panels, this screen does not feature the usual heavy and aggressive Anti-glare (AG) coating which can sometimes lead to grainy and dirty looking images. Instead it uses a light AG screen coating and as a result the colours look more clean and crisp, the image quality is sharp and whites in particular look more pure than they do on heavy AG coated screens. It isn't a full glossy solution which adds another level of clarity and changes the overall feel of the screen, but it is an improvement over the heavy AG coating of some other IPS screens, including the previous Dell U2711. A positive change and hopefully something we will start to see more of with future IPS screens.

 

You can use our settings and try our calibrated ICC profile if you wish, which are available in our ICC profile database. Keep in mind that results will vary from one screen to another and from one computer / graphics card to another.

 

 

Dell U2713H - Calibrated Settings, sRGB Mode

Monitor OSD Option	Calibrated Settings
Brightness	19
Contrast	50
RGB Channels	n/a
Preset Mode	sRGB

	Calibrated Settings, sRGB mode
luminance (cd/m2)	119
Black Point (cd/m2)	0.17
Contrast Ratio	721:1

 

I also carried out the calibration in the monitors 'sRGB' emulation mode. Here you do not have access to the RGB channels at all, and so the only hardware changes being made are to the brightness control. The other corrections would be carried out at a graphics card LUT level through the profiling process. However this would of course allow you to work with the smaller sRGB colour space which we'd already established was being well emulated in this preset. The results were again very pleasing. Targets for gamma and white point had all been met nicely, correcting the 7% and 4% deviations respectively we had seen out of the box in this mode. The luminance had been corrected to the desired level with the change in the brightness control, and the static contrast ratio was a moderate 721:1 after calibration. Colour accuracy had been corrected from the already very good dE 1.5 average we had seen out of the box thanks to the factory calibration, now down to 0.5 dE average. Testing the screen with various colour gradients showed smooth transitions on the whole, with some slight gradation and some very slight banding in some darker shades due to the graphics card corrections made. You can use our settings and try our calibrated ICC profile if you wish, which are available in our ICC profile database.

 

Dell U2713H - Calibrated Settings, Adobe RGB Mode

Monitor OSD Option	Calibrated Settings
Brightness	19
Contrast	50
RGB Channels	n/a
Preset Mode	Adobe RGB

	Calibrated Settings, Adobe RGB mode
luminance (cd/m2)	120
Black Point (cd/m2)	0.16
Contrast Ratio	778:1

 

I also carried out the same process in the Adobe RGB preset mode. This too was factory calibrated out of the box and had offered a pretty reliable setup, along with an accurate emulation of the slightly smaller (compared with the backlights native gamut) Adobe RGB colour space. The calibration helped correct the slight 5% deviance we'd seen by default in the gamma. We also corrected the small 1% white point deviance from the factory setting. Contrast ratio remained quite close to the default 810:1 we'd seen in this mode, now being measured at 778:1 after profiling. Colour accuracy had been corrected, now with a 0.4 dE average and maximum 1.5 measured when validating the produced profile. Testing the screen with various colour gradients showed smooth transitions on the whole, with some slight gradation and some very slight banding in some darker shades due to the graphics card corrections made. You can use our settings and try our calibrated ICC profile if you wish, which are available in our ICC profile database.

 

 

 

 

Hardware Calibration

 

Updated 29 October 2014

 

One thing which separates this screen from many mainstream monitors, including the previous Dell 27" offerings, is the support for hardware calibration. Users can program the monitors 14-bit Look Up Table (LUT) if they have the appropriate software and hardware to achieve higher levels of accuracy, something which professional users require and one of the reasons why pro-grade screens from NEC and Eizo have always been popular in such markets. The software part of is easy, Dell provide their own free "Color Calibration Solution" software which is available to download from Dell.com. This is a piece of software made for Dell by X-rite and allows the user to access the hardware LUT to calibrate the screen in two available modes. Currently the latest version is v 1.5.3 for Windows operating systems (Win 7, 8, 8.1). There is also now a Mac OS version available here. These versions should work with all the hardware calibration supporting UltraSharp models, despite the download page only listing the UP2414Q and UP3214Q.

 

Important: The second part is not so easy however as you require a compatible calibration tool to work with this software and allow hardware calibration. Dell, or rather the software provider X-rite, have locked this so that you can ONLY use the X-rite i1 Display Pro colorimeter, or i1 Pro / i1 Pro 2 spectrophotometers. Other devices are NOT compatible at all, including the i1 Display 2, ColorMunki, Spyder series or any other colorimeter. The software was co-designed between Dell and X-rite and X-rite have recommended the use of the i1 Display Pro or i1 Pro devices with the wide gamut backlighting.

 

Users who already have another type of colorimeter will be disappointed as although they will be able to software calibrate their screen (profiling) as we have done in the previous sections as normal, they will not be able to use it for the all-important hardware calibration. I'm sure consumers will argue they should not need to buy a new colorimeter to use with this screen and that other devices should be compatible. We would be inclined to agree, but unfortunately the reality is that you can only take advantage of the hardware calibration of the U2413 (or 27" U2713H / 30" U3014) if you have a compatible X-rite device. If you don't own any device yet, these are obviously the ones to get for these displays.

 

 

Dell UltraSharp Color Calibration Solution (v1.0.0.0 at time of writing)

 

 

We installed the Color Calibration software to test it out. When you load it up you are presented with the above screen with a pretty basic set of options to select. You can choose whether you are going to calibrate either CAL1 or CAL2 modes, and once you've done so you can quickly and easily switch between them from within the monitors OSD in the preset section. This allows you to set up a couple of custom modes, perhaps working with different colour spaces (sRGB vs Adobe RGB for instance) or with different target white points, gamma curves or luminance levels.

 

 

You can then choose from the 'color space' drop down to define your targets. Most have preset settings which you cannot change. For instance if you choose sRGB you cannot change white point or gamma targets manually. You can however alter the target luminance manually for each which is good.

 

 

There is however a 'custom' mode which gives you further control over the settings, allowing you to define a colour space manually (you must know your required coordinates for this), white point, gamma and luminance. This gives the user more flexibility where needed.

 

 

 

The other options and menus are very limited. If we enter the 'info' section we get a small pop up window above explaining some of the options. You may note here reference to the U3014 which further confirms our understanding that the new 30" model will be called the U3014 and not the U3013 when it is released soon.

 

 

 

The 'preferences' menu gives you only one option to choose whether you are using ICC profile v2 or v4. Oddly the other menu within the 'help' tab for 'check for updates' goes to a dead link on X-rites website, presumably something which will be fixed at some point soon.

 

 

Once you've defined your targets in the first section you can press 'next' to move into the calibration itself. As you can see above, if you do not have an i1 Display Pro connected you are not able to progress any further. There is a link there if you do not have one, which again goes to a dead page on X-rite's site at the moment. A bit of a poor show but presumably one which will be fixed soon and probably a page to tell you more about the device or where to purchase it.

 

 

Updated 31 January 2013

 

We now have access to an i1 Display Pro colorimeter device from X-rite and so are able to complete the hardware calibration and look at the process in a bit more detail. We first of all stuck to the "native" colour space from the first page of options and defined our target luminance as our usual 120 cd/m². We selected CAL1 as the preset to load this all in to on the monitor. You have two modes available in the menu so you can do hardware calibrations to two different targets or colour spaces if you wish.

 

 

This time if you press 'next' with an i1 Display Pro connected you are presented with the above screen asking you to attach and position your device on the screen. Pressing 'next' again enters into the fully automated hardware calibration process. The bottom of the screen tells you there are 7 steps to this process. During the process the bottom of the screen tells you these are 1) optimizing brightness and then contrast, 2) calibration using 44 colour patches shown on the screen, 3) calibration using 67 colour patches, 4) building color transform, 5) loading input data tables, 6) loading output data tables, 7) setting target luminance. In fact there is an 8th stage which involves measurement of 119 colour patches. Overall the process takes ~7 minutes to complete but at least it's fully automated.

 

 

 

At the end you are asked to save your profile.

 

 

Lastly it confirms the save and asks if you want to be reminded to re-calibrate in the future. The software then closes. There are no validation reports or anything, you are presumably just to assume it has corrected everything and set up the screen how you asked. The software is certainly lacking in this area with no reporting feature of any kind. The screen is now in the CAL1 preset mode within the OSD menu.

 

Thankfully we can revert to some other software to validate some of the results achieved from this method. We tested the screen again using the test and report functionality from within LaCie's Blue Eye Pro software and used our i1 Pro spectrophotometer to see how well setup the hardware calibration seemed to be.

 

Update 14/1/14 - As we have learnt from our more recent review of the Dell UP3214Q, Dell and X-rite have now updated their calibration software package to include some validation and reporting elements which brings the software more in line with their i1 Profiler package. See our UP3214Q review for more information.

 

Dell U2713H - Hardware Calibrated Settings, Native Gamut Mode

	Hardware Calibrated Settings, Native Gamut
luminance (cd/m2)	124
Black Point (cd/m2)	0.13
Contrast Ratio	964:1

 

The screen has been kept at its native gamut, with the colour space stretching beyond the Adobe RGB space and not being cut back at all to any smaller emulated space. We can see that the gamma curve has been corrected pretty well now, helping to address the 15% deviance we'd seen in the monitors 'standard' preset mode (which is based on the full native gamut of the backlight). This was now 2.2 on average with a small 2% deviance. The white point was measured at 6028k so it seems that again the target defined by Dell for white point in their calibration is 6000k. We'd seen this as the target from our factory calibration report. You can't manually change the white point target within the software without going specifically into the 'custom' options mode. Here we had just used the 'native' mode in the calibration software which seems to be set to achieve a 2.2 gamma and a 6000k white point. The luminance had been corrected pretty nicely here which was good, and the resulting contrast ratio of 964:1 was excellent and even better than we'd achieved in the software calibration tests using the monitors native gamut (when calibrating in the 'custom color' mode). Colour accuracy was also very good with dE average of 0.6. The hardware calibration was a success and had worked very well. The only downside was the white point (compared with our targets), but that will hopefully be possible to correct using the custom mode. We will test that in a moment.

 

 

Dell U2713H - Hardware Calibrated Settings, Adobe RGB Gamut

	Calibrated Settings, Adobe RGB mode
luminance (cd/m2)	126
Black Point (cd/m2)	0.16
Contrast Ratio	766:1

 

We performed the same process again, but this time choosing the 'Adobe RGB' setting within the software. This is designed to emulate the slightly smaller Adobe RGB space, much like the specific Adobe RGB preset mode in the OSD menu. We had already tested the OSD preset mode based on its factory calibration and determined it had emulated that colour space well, been pretty close to our target white point (6416k, 1% out) but left us with some gamma discrepancies (2.3 average, 5% out).

 

Through the hardware calibration in this mode we can see that the monitors native colour space has been reduced a little, but it doesn't match the Adobe RGB reference as closely as the specific preset mode from the OSD menu. This is likely down to small differences between the measurement sensors of the X-rite i1 Display Pro colorimeter and the i1 Pro spectrophotometer, but is nothing too severe. The resulting colour space coverage using this defined setting and the i1 Display Pro was a little wider than the Adobe RGB space but not by much. Gamma had been improved again to 2.2 average was a small 2% deviance. White point was now 6266k so actually a bit closer to our target. Luminance had again been corrected pretty nicely, with the small deviance likely down to the differences between the calibration tools again. Contrast ratio was 766:1 which is pretty much what we'd seen from our software calibration as well.

 

Dell U2713H - Hardware Calibrated Settings, sRGB Gamut

	Calibrated Settings, sRGB mode
luminance (cd/m2)	124
Black Point (cd/m2)	0.17
Contrast Ratio	716:1

 

Lastly we used the sRGB option to calibrate to this smaller colour space. This was emulated very well in fact and matched the coverage offered by the specific OSD menu preset mode. Gamma was nicely corrected to 2.2, sorting out the 7% deviance we'd seen out of the box. The white point was 6250k so again a little out from the target. Contrast ratio was 716:1 and pretty much what we'd achieved through our software calibration.

 

Dell U2713H - Hardware Calibrated Settings, Custom Gamut

	Calibrated Settings, Custom Gamut (Native)
luminance (cd/m2)	125
Black Point (cd/m2)	0.17
Contrast Ratio	741:1

 

Finally we used the 'custom' option in the software. We left the colour coordinates at the native gamut of the backlight, but we defined 2.2 gamma and 6500k white point. The resulting calibration corrected the gamma nicely to 2.2 but the white point was still a little out at 6274k. Perhaps this is down to the X-rite i1 Display Pro device and its measurement of GB-LED backlights, and perhaps it is not quite measuring the white point correctly. You could probably compensate for this by aiming for a slightly higher white point target through this custom mode.

 

 

Overall the process was pretty simple to use although it did take a while for each calibration. The software is lacking any kind of reporting feature which is a shame so you just have to trust that the targets have been achieved, or find some other software which will allow you to validate the results. The native and sRGB modes in the software produced the required colour space well, but the Adobe RGB mode was a little off and not quite as reliable in this regard as the factory calibrated mode available in the OSD menu. Gamma was corrected pretty well to ~2.2 in all the modes which was good, but the white point seemed to be 200 - 300k out. The native mode seemed to be set to achieve a white point of 6000k perhaps which it did well. We are not sure what the other Adobe RGB and sRGB modes were designed to reach as a white point but by default they resulted in a colour temperature of ~6250k. The custom mode allows you to define your targets if you wish but it does seem that the X-rite i1 Display Pro is measuring the white point about 200 - 300k out. Either that or the software is not quite achieving what you are asking it to. Not a huge difference of course, just a shame the software isn't compatible with other devices which we've already covered.

 

While the Adobe RGB and sRGB options had resulted in a contrast ratio equivalent to what we'd seen through software calibrations, the 'native' mode had resulted in a much higher contrast ratio of 964:1 which was great news. This seemed to be the optimum contrast ratio post-calibration we could achieve, through either  software or hardware methods.

 

As a side note, the uniformity compensation feature is not available when using the CAL1 and CAL2 modes. We will look at that feature later in the review but without meaning to spoil that section, it doesn't seem to do much in reality anyway. It is a little odd however that Dell have not made the two available together. Had the feature worked properly (as it did on the Dell U2913WM we've also tested since), it would have been nice to be able to combine it with the hardware calibration modes.

 

 

Calibration Performance Comparisons

 

The comparisons made in this section try to give you a better view of how each screen performs, particularly out of the box which is what is going to matter to most consumers. When comparing the default factory settings for each monitor it is important to take into account several measurement areas - gamma, white point and colour accuracy. There's no point having a low dE colour accuracy figure if the gamma curve is way off for instance. A good factory calibration requires all 3 to be well set up. We have deliberately not included luminance in this comparison since this is normally far too high by default on every screen. However, that is very easily controlled through the brightness setting (on most screens) and should not impact the other areas being measured anyway. It is easy enough to obtain a suitable luminance for your working conditions and individual preferences, but a reliable factory setup in gamma, white point and colour accuracy is important and not as easy to change accurately without a calibration tool.

 

From these comparisons we can also compare the calibrated colour accuracy, black depth and contrast ratio. After a calibration the gamma, white point and luminance should all be at their desired targets.

 

Default setup of the U2713H in the non-factory calibrated "standard" mode was pretty poor really. There was a large 15% deviance in gamma, although this was very similar to the deviance we'd seen from the older U2711. The 6% white point deviance was not too bad although the image was a little cool.
 

 

 

Updated 31 January 2013

 

We have updated this section since our hardware calibration tests. The calibrated black depth and contrast ratio of the U2713H were excellent for an IPS panel really if you can carry out a hardware calibration and are happy to remain with the monitors native gamut mode. We achieved 964:1 through this method, although when emulating smaller colour spaces like Adobe RGB and sRGB the contrast ratio was reduced somewhat (766:1 and 716:1 respectively). This 964:1 contrast ratio was also more than we'd achieved through our software calibration which at best had returned 800:1 in the 'custom color' mode. The contrast ratio offered by the U2713H should be more than adequate for most users still even if you can only carry out software calibrations or want to work in the smaller colour spaces. Those needing a higher CR may want to consider other technologies like AMVA.

 

 

Contrast Stability

The luminance range of the screen was excellent. At the top end the panel reached a high 301.17 cd/m² which while it was actually a little short of the specified maximum luminance of 350 cd/m², should still be more than most users would ever need as an upper limit nevertheless. At the lower adjustment end it could reach down to a very low 57.62 cd/m² which was close to the specified 50 cd/m² minimum. This meant the screen should be perfectly fine even in darkened room conditions, and for those who like to run at a lower luminance setting. A brightness setting of ~16% should return you a default luminance of around 120 cd/m² as well. Black point ranged from 0.35 cd/m² down to 0.07 cd/m² with the backlight adjustments.

We have plotted the luminance trend on the graph above. The screen behaves as it should, with a reduction in the backlight intensity controlled by the reduction in the OSD brightness setting. This was not a linear relationship though. As you can see from the graph the settings between 100 and 50% actually controlled a pretty small adjustment range between 301 cd/m², and 253 cd/m². The changes in the OSD to the brightness control were only bringing about a small change in the observed luminance of the display. From 50% downwards the luminance changed more dramatically as shown by the steeper line on the graph. This range from 50 to 0% allowed you to adjust the luminance from 253 all the way down to 58 cd/m², giving the user a more significant control over the actual luminance of the display. This is all achieved without the use of Pulse Width Modulation as well which is positive news.

Average contrast ratio in the standard default preset mode was measured was 846:1 which was good for an IPS panel really. In fact this was measured in the 'standard' preset mode and you could improve on this by using some of the other presets if needed. It was pretty stable across the adjustment range with some small deviations at the lower end of the brightness scale.

Dynamic Contrast

We tested the DCR feature in both the movie and game preset modes while at default settings (50% default brightness). On these Dell screens you can observe the changes being made in the OSD by looking at the energy meter in the top right hand corner. Switching to this mode in normal office-type applications showed no initial change to the energy bar and the screen seemed to remains at a luminance similar to the default 50%. When switching between an almost all-white and an almost all-black screen there was hardly any change at all to the luminance of the screen. There was very little change detectable to the naked eye but you could see the energy bar go down by 1 bar in the OSD menu. This change took about 1 second to complete.

Oddly in the movie preset mode the contrast ratio was pretty poor at 551:1 even with this very slight dynamic adjustment going on. We measured a static contrast ratio in this mode with DCR turned off at a very close 540:1 anyway so it seemed this mode did not offer the best contrast ratio anyway. In the game preset mode again the DCR seemed to hardly work at all in these tests with only a 1 bar adjustment in the OSD being visible. We obtained a DCR of 865:1 which was not really any better than the static contrast ratio we'd seen in the default standard preset modes. When comparing a mostly white and mostly black image the DCR seemed to be doing very little at all.

We tested the screen with a completely black screen as well and you could tell from the OSD energy meter that it was then able to control the backlight a lot more, down to the low setting of ~1% by the look of the energy bar (which showed 1 bar). This would in theory give you a better DCR of around 3585:1 but it should be noted that it would be extremely rare to ever see a 100% black image in real use and so this is more of a theoretical DCR than a realistic, practical DCR. Our tests of an almost all-black image are more realistic for actual use, and the DCR didn't offer us much there.

You'd have to be turning the backlight completely off on an all-black image to achieve anything higher than this though and to get anything near the crazy spec being quoted. Some screens do actually do that which allows for exaggerated laboratory testing and their resulting specs, but in the case of the U2713H it was not turning the backlight off. In normal use, the DCR is pretty much useless.

 

Viewing Angles

Above: Viewing angles shown from front and side, and  from above and below. Click for larger image

Viewing angles of the U2713H were very good as you would expect from an IPS based panel. Horizontally there was very little colour tone shift until wide angles past about 45°. Contrast shifts were slightly more noticeable in the vertical field but overall they were very good. The screen offered the wide viewing angles of IPS technology and was free from the very restrictive fields of view of TN Film panels, especially in the vertical plane. It was also free of the off-centre contrast shift you see from VA panels and a lot of the quite obvious gamma and colour tone shift you see from some of the modern AMVA and PVA offerings. All as expected really from a modern IPS panel.

Above: View of an all black screen from the side. Click for larger version

On a black image there is a characteristics IPS white glow, but in normal working conditions this shouldn't present much problem. The above image was taken in a darkened room to demonstrate the white wide angle glow when viewing a black screen. There is no A-TW polarizer on this panel which is rarely used now in the market but was implemented on some older screens to improve the off centre black viewing.

If you are viewing dark content from a close position to the screen you can sometimes see this pale glow on parts of the screen towards the sides and corners because of your proximity to the screen and your line of sight. The edges of the screen are at an angle from your line of sight which means you pick up this white glow to a smaller degree. This disappears as you move backwards away from the screen where the line of sight does not result in a wide angle view of parts of the screen and you can see the screen largely from head on. This glow should not be mistaken for backlight bleeding which would not disappear as you changed your line of sight or angle of viewing.

Panel Uniformity

We wanted to test here how uniform the brightness was across the screen as well as identify any leakage from the backlight in dark lighting conditions. First of all measurements of the luminance were taken at 35 points across the panel on a pure white background. The measurements were taken using BasICColor's calibration software package, combined with the NEC customised X-rite i1 Display 2 colorimeter. The below uniformity diagram shows the difference, as a percentage, between the luminance recorded at each point on the screen, as compared with the reference point of a calibrated 120 cd/m². This is the desired level of luminance for an LCD screen in normal lighting conditions, and  the below shows the variance in the luminance across the screen compared with this point. It is worth noting that panel uniformity can vary from one screen to another, and can depend on manufacturing lines, screen transport and other local factors. This is only a guide of the uniformity of the sample screen we have for review.

The U2713H features a uniformity compensation feature which we will test here as well, but first of all we left this setting off.

Luminance Uniformity

Uniformity of Luminance
Uniformity Compensation = Off

The luminance uniformity of the U2713H was not great sadly. The centre of the screen was notably brighter than the edges where the luminance dropped down to 93 cd/m² minimum in the top left and right hand regions (-28% deviance). Only ~25% of the screen was within 10% deviance of the central point which wasn't great. Given the high cost and market position of this screen we had hoped for me in terms of luminance uniformity. To be fair we hadn't experienced any issues in day to day use with this luminance uniformity variation, but the performance in these tests was a little disappointing.

Uniformity Compensation Feature

The U2713H features a uniformity compensation feature within the OSD menu as shown above. This isn't something Dell have made much fuss of oddly, but it's a feature again normally reserved for pro-grade screens. We've seen similar technologies used on NEC and Eizo screens in the past with some positive results. The Dell manual states: "Uniformity Compensation adjusts different areas of the screen with respect to the centre to achieve uniform brightness and colour over the entire screen. For optimal screen performance, Brightness and Contrast for some preset modes (Standard, Color Temp) will be disabled when Uniformity Compensation is turned On. When Uniformity Compensation is turned On, Energy Smart cannot be activated. NOTE: Screen Uniformity performance is optimized at default out of factory luminance setting."

There are options available for "calibrated" and "user" as well as an off setting. The calibrated option is supposed to represent a factory setup and as per the manual this is apparently optimised when in the screens default setup and at the default 50% luminance. According to the manual the user mode is "reserved for Dell approved user calibration software settings" although we can't see any options within the calibration software of Dell Display Manager software to do anything related to panel uniformity. Update 31 January 2013 - We have since confirmed with Dell engineers that the 'user' feature was abandoned late in development on these new UltraSharp screens and is not available, with no plans to make it available. It should be removed really from the manuals and OSD menu which Dell are looking at for future revisions.
 

Although the manual states that the factory calibrated uniformity compensation mode is optimised for use at the default 50% brightness, it should also offer improvements in theory at other brightness settings. After all, who is going to operate their screen at the high default luminance day to day? To start with we left the screen set at our calibrated 120 cd/m² setting and measured the luminance uniformity again while in the "calibrated" mode:

Uniformity of Luminance
Uniformity Compensation = Calibrated

Disappointingly the "calibrated" uniformity compensation mode seemed to make very little difference at all to the actual overall uniformity of the panel. There were still fairly large deviations along the left and right hand edges of the screen, with luminance dropping down by -26% in these regions. The overall picture was the same as with the setting off, with ~25% of the screen being within 10% deviance of the target. This mode did seem to impact contrast ratio very slightly as well, dropping by about 20:1.

We tested this "calibrated" mode again at default screen settings, returning to the factory 50% brightness and the standard preset mode. The manual suggested that this would return optimum performance from this correction feature, but in reality the story was the same as before (uniformity graph available for reference here). This supposed factory calibrated setting for the uniformity compensation feature seemed to do nothing in practice to correct the rather disappointing luminance uniformity of the screen.

Uniformity of Luminance
Uniformity Compensation = User

While there isn't any method for adjusting the so-called "user" mode uniformity compensation option we tested the screen again at the default settings. When you switch to this mode in the OSD there is a noticeable drop in the screens luminance although the static contrast ratio remains as it was in the calibrated mode (again about 20:1 less than the default where this feature is turned off). We re-adjusted the central point to 120 cd/m² and took the measurements across the screen as before. As you can see from the above, the picture was the same again. No improvement in the luminance uniformity of the screen with some large deviations still along the edges.

 

Colour Temperature / White Point Uniformity

We also extended our tests in this area to establish how uniform the colour was across the screen. We measured the white point (colour temperature) deviance compared with a central point calibrated to our 6500k target. First of all we carried out this test with the uniformity compensation feature turned "off".

Uniformity of White Point / Colour Temperature
Uniformity Compensation = Off

As you can see, the colour temperature was very uniform across the panel with only small deviations across the screen. The bottom two corners were a little cooler where they deviated to ~6950k (-7.25% deviance maximum). There were a couple of areas towards the top of the screen where the colour temperature was a little warmer as well, but only by around 1.5% difference maximum, so nothing significant at all. This was all with the uniformity compensation feature turned off, so while we had been a little disappointed with the luminance uniformity of the screen, the colour temperature was at least stable.

Uniformity of White Point / Colour Temperature
Uniformity Compensation = Calibrated

We then turned the uniformity feature back on to 'calibrated' and ran the same tests. As you can see the results are pretty much identical again, with no significant difference. In the case of white point, that's probably a good thing since the default performance with the setting off was very good anyway.

This does however lead us to the conclusion that the uniformity compensation feature on this model is useless really. It seems to do nothing to correct the luminance uniformity variations we'd seen from our sample (may vary of course between sample units) and didn't change anything compared with if you just leave the setting off. The white point uniformity was actually very good on our sample but again the compensation feature didn't alter this at all. For now, the feature seems to be a gimmick only and the factory calibrated mode doesn't seem to do anything different to if you just leave it turned off, other than maybe reduce your contrast ratio a little.

Backlight Leakage

Above: All black screen in a darkened room. Click for larger version

As usual we also tested the screen with an all black image and in a darkened room. A camera was used to capture the result. There was no obvious backlight bleeding at all to the naked eye and the uniformity looked very good, even in a darkened room. The camera captured some slight clouding from the corners, mainly on the right hand side but this was very slight and not something which you should notice in practice. A pleasing result here.

 

General and Office Applications

The U2713H feature a massive 2560 x 1440 WQHD resolution which is only just a little bit less vertically than a 30" screen. The pixel pitch of 0.231mm is very small as a result, and by comparison a standard 16:10 format 24" model has a pixel pitch of 0.270mm and a 30" model has 0.250mm. These ultra-high resolution 27" models offer the tightest pixel pitch and therefore the smallest text as well. We found it quite a change coming from 21.5 - 24" sized screens, even those offering quite high resolutions and small pixel pitches.  Some users may find the small text a little too small to read comfortably, and I'd advise caution if you are coming from a 19" or 22" screen for instance where the pixel pitch and text are much larger. I found a 30" screen to be quite a change with text size when I first used one, and this is very similar and even a little bit smaller! I still personally prefer the slightly larger text of a 24" model myself, but I expect I could happily get used to the added resolution on these models given time. The extra screen size also takes some getting used to over a few days as there really is a lot of room to work with.

The massive resolution is really good for office and general use, giving you a really big screen area to work with. It is a noticeable upgrade from a 24" 1920 x 1200 resolution, and it's good to see Dell have opted to stick with the high res panel here rather than reverting to some other 1920 x 1200 / 1920 x 1080 res panel as you may find in other 27" models. For those wanting a high resolution for CAD, design, photo work etc, this is a really good option. The image was very sharp and crisp and text was very clear. With its WQHD display, you enjoy 77% more desktop space than a full HD screen to spread out your windows and palettes.

The light AG coating is also a very positive move when it comes to these kind of uses and we had been pleased when Dell made this switch before with the U2713HM. The new lighter coating ensures that white backgrounds of office documents looked good, and did not suffer from the overly grainy and dirty feel of some competing IPS panels featuring heavy, aggressive AG coating - including the old U2711. It also remained free from the reflections you might experience from a full glossy solution so seems to be a good half-way between the two. The wide viewing angles provided by the IPS panel technology on both horizontal and vertical planes, helps minimize on-screen colour shift when viewed from different angles. The default setup of the screen was not great in the standard mode, but the factory calibrated Adobe RGB and sRGB modes were better, providing a more reliable gamma and white point setup which should produce a decent image for office work. They also allowed you to choose between a wide gamut or standard gamut colour space which was very useful, and many users may prefer to use sRGB to avoid complications with colour management and oversaturation of colours. If you follow our basic OSD adjustments from our calibration process (and maybe also try our calibrated ICC profile) you should be able to get a better setup, even without a colorimeter of your own. Of course given this is a high end screen aimed at professional users it is logical to expect many people who purchase the screen will already have a calibration tool of their own, or at least plan to buy one soon. With a calibrator you can of course obtain even more accurate setups which is great news, although you do need to be wary of the limitations of the hardware calibration feature which we talked about earlier. If you've not got a device yet and plan to buy one, make sure you buy an X-rite i1 Display Pro if you want to use the hardware calibration. That would also be a good device for use with other displays as well.

There is a specific 'paper' preset mode available within the OSD menu which makes the image darker and more yellow. This might be useful to some for certain reading conditions, but with the wide range of adjustments and modes available it should be easy enough to get an optimum setup for your uses.  Out of the box the luminance was too high and so you will want to turn this down a fair amount to obtain a setting comfortable to you in your lighting conditions. A setting of around 16% brightness should give you a luminance of around 120 cd/m² out of the box. The brightness control affords you a good range of adjustments as well, allowing you to go up to ~301 cd/m² and down as low as ~58 cd/m². Even those wanting to use the screen in low light conditions should find the adjustment range more than adequate. Another thing to note while we are talking about the brightness control is that the screen does not use Pulse-Width modulation (PWM) to control backlight dimming and so those who suffer from eye fatigue or headaches associated with flickering backlights need not worry here. The screen is also free from the so-called "cross-hatching" issue which some users noticed on the U2713HM.

Another issue which some users reported from the U2713HM was image retention in some circumstances. Often easy to re-create by leaving a white window on a black background for a fair amount of time, and then switching to a grey background where an after-image was left. We tested this on the U2713H and couldn't see any issues ourselves. The screen did however exhibit a very feint hum from the screen if you listen very closely during normal use. The screen does also suffer from a buzzing issue though in circumstances, much like the U2713HM did. On certain content, mostly when viewing a single large text document or spreadsheet full screen, a noticeable buzzing noise is introduced. I've not really experienced it during normal every day use, but in the "right" circumstances it is there. This seems to be down to the capacitors and through our conversations before with dell regarding the U2713HM, we know this is something they are looking at. I suspect if they resolve it with a future revision of the U2713HM, the same will be done with the U2713H. To be totally fair, this buzzing noise is a minor issue and quite hard to actually produce. You're unlikely to hear it during normal uses so don't let it put you off. It is there though so those who were bothered by it on the U2713HM need to be aware.

The screen offers a 4 port USB 3.0 hub which is useful, especially with 2 ports located on the left hand edge for easy and quick access. There is also a 9-in-1 card reader which is good news and something personally I've found useful on previous Dell models. Nice to see it returning here for the U2713H. There was a good range of ergonomic adjustments available which were all pretty easy and smooth to use. The screen even offers a rotation function which is probably impractical at this size. The VESA mounting support may also be useful to some people. With DisplayPort and DL-DVI both supporting the full 2560 x 1440 resolution you should have a decent choice for your PC connectivity.

 
Above: photo of text at 2560 x 1440 (top) and 1920 x 1080 (bottom)

The screen is designed to run at its native resolution of 2560 x 1440 and at a 60Hz recommended refresh rate. You will need a Dual-link DVI output or DisplayPort from your graphics card in order to handle that resolution. However, if you want you are able to run the screen outside of this resolution. We tested the screen at a lower 1920 x 1080 resolution to see how the screen handles the interpolation of the resolution, while maintaining the same aspect ratio of 16:9. At native resolution the text was very sharp as you can see from the top photograph. When you switch to a lower resolution the text is larger of course but actually still retains a lot of its sharpness. A decent performance really if you did need to run outside of native resolution for whatever reason. We would recommend native resolution wherever possible for maximum picture quality and screen real-estate of course.

 

Responsiveness and Gaming

The U2713H is rated by Dell as having a 6ms G2G response time which implies the use of overdrive / response time compensation (RTC) technology, used to boost pixel transitions across grey to grey changes. There is no user control over the overdrive impulse within the OSD menu and so we are reliant once again on Dell's factory setup. The part being used is the LG.Display LM270WQ3-SLA1 AH-IPS panel. Have a read about response time in our specs section if any of this is new to you.

Updated 31 January 2013

We have updated this section of the review with our new response time testing method. This uses an oscilloscope and photosensor to measure the pixel response times across a series of 20 different transitions, in the full range from 0 (black) to 255 (white). We also calculate the average grey to grey (G2G) response time and provide an evaluation of any overshoot present on the monitor.

We use an ETC M526 oscilloscope for these measurements along with a custom photosensor device. Have a read of our article for a full explanation of the testing methodology and reported data.

On the whole the pixel transitions were pretty fast. The average G2G response time was measured at 7.2ms which was just a little slower than the specified 6ms G2G from the manufacturer, but still very respectable. Some black to grey changes (0-50, 0-150) were a little slower at ~11 - 13ms. There was only minimal difference between the average G2G rise time (changes from dark to light shades) and the average G2G fall time (changes from light to dark shades). Interestingly the changes to a full white shade (255) were the fastest where it seems the overdrive impulse was being applied the most aggressively.

Unfortunately if we evaluate the Response Time Compensation (RTC) overshoot then the results are not as pleasing. There is some significant overshoot evident with transitions from dark to light shades, particularly when changing to white (255). We had already noted that the response time for these transitions was very low and it seems that the overdrive impulse is being applied very aggressively here. While it may be speeding up the pixel transitions it is causing a large degree of overshoot. For the changes to 200 and 255 the average RTC overshoot was a high 23.8% which was not very good at all. In practice this results in an obvious trailing image on certain transitions which could prove distracting. Transitions from light to dark are not affected as much but there are still some errors with the transitions which are close together (e.g. 255 - 200 and 200 - 150). We can conclude that the response times of the U2713H are pretty good, but the RTC overshoot may prove problematic to some users.

 

Display Comparisons

The screen was also tested using the chase test in PixPerAn for the following display comparisons. As a reminder, a series of pictures are taken on the highest shutter speed and compared, with the best case example shown on the left, and worst case example on the right. This should only be used as a rough guide to comparative responsiveness but is handy for a comparison between different screens and technologies.

27" 6ms G2G LG.Display AH-IPS

In practice the Dell U2713H showed fairly low levels of motion blur although some was detectable to the naked eye and picked up in these tests. There was nothing severe and no obvious ghosting which was good. In these tests we did not see any obvious overshoot problems which was interesting but this is likely to be down to the colour transitions being made in this program. The transitions are from light to dark shades with the movement of the car and we know from our oscilloscope tests that there was minimal overshoot in those circumstances. Thankfully our oscilloscope method allows us to measure a wider range of transitions and provide a more complete picture. We had originally concluded that the RTC overshoot was minimal on this model based on these tests but in fact it is quite varied and can manifest itself more severely in the dark > light pixel changes.

 

27" 6ms G2G LG.Display AH-IPS

27" 6ms G2G LG.Display H-IPS

27" 8ms G2G LG.Display AH-IPS

We have provided a comparison of the U2713H above against the 2 other 2560 x 1440 resolution 27" Dell screens we have tested. On the new model there was some slight motion blur evident but nothing too severe, although it appeared to be a little less in practice on the Dell U2713HM as you can see from the above. While we did not see any overdrive artefacts on this model due to the pixel transitions being made in these tests we had seen worse when we tested the Dell U2711 where it was quite noticeable in the form of a dark trail. This was actually more noticeable in practice as well with other tests and fast moving images. Considering the market position of the U2713H the gaming performance should be adequate and any overshoot you do experience in some transitions shouldn't represent a major issue to the main target audience.

 

27" 6ms G2G LG.Display AH-IPS

27" 12ms G2G LG.Display H-IPS

27" 5ms G2G Samsung PLS (Trace Free = 40)

27" 5ms G2G Samsung PLS (Response Time = Faster)

We have provided a comparison of the U2713H above against 3 other popular 2560 x 1440 resolution 27" screens we have tested which all use IPS (or the very similar PLS) panel technology. The U2713H was quite comparable to the HP ZR2740w v2, perhaps being a little faster in practice with a slightly less noticeable blurring. The PLS-based Asus PB278Q and Samsung S27A850D were faster still, showing no obvious ghosting and no obvious artefacts caused by the RTC impulse which was pleasing at certain optimum settings.

 

27" 6ms G2G LG.Display AH-IPS

27" 5ms G2G Samsung PLS (Response Time = Faster)

27" 7ms G2G LG.Display p-IPS (response improve = on)

27" 6ms G2G LG.Display H-IPS (Overdrive = On)

We have also provided a comparison of the U2713H against 3 competing professional grade monitors. Given the price point and market position of the U2713H it is likely that some buyers will want to compare with the high end NEC, Samsung and Eizo models in the market. The U2713H performed comparatively well on the most part. The Samsung S27B970D with its PLS panel was faster in practice and showed less blurring of the moving image. The NEC PA271W and Eizo SX2762W feature overdriven IPS panels as well like the Dell screen. They did offer pretty low levels of motion blur and some decent performance really considering they are not gamer orientated screens, but there were some overshoot issues in some cases, particularly evident on the Eizo tests.

27" 6ms G2G LG.Display AH-IPS

24" 7ms G2G LG.Display AH-IPS

27" 5ms G2G LG.Display AH-IPS (overdrive = medium)

27" 4ms G2G AU Optronics AMVA (AMA = Premium)

We can also compare the U2713H  against a couple of other 27" models, this time with lower 1920 x 1080 resolutions. The AOC i2757Fm and Dell S2740L show a fairly similar performance in practice to the U2713H with a similar level of motion blur. However, in the case of the Dell, a dark overshoot is again introduced due to an aggressive overdrive impulse. The BenQ GW2750HM is a little different as it is based on a 1920 x 1080 resolution AMVA panel and not IPS technology like the others here. It was quite comparable to the U2713H  overall, but it did show some dark trailing, but not quite as noticeable as on some of the other models we have discussed.

 

27" 6ms G2G LG.Display AH-IPS

30" 7ms G2G LG.Display H-IPS

24" 6ms G2G AU Optronics AMVA

24" 8ms G2G LG.Display e-IPS

24" 6ms G2G LG.Display H-IPS

We can also compare the U2713H with some of the other Dell screens we've tested here, this time in other sizes including the 24" U2410 and U2412M and the 30" U3011 (soon to be replaced by the U3014 incidentally). The U2713H is quite close in practice to the U3011 in these tests, while the three 24" models are a little faster. They may have faster pixel transitions thanks to a more aggressive overdrive impulse, but in the case of the S2440L and U2412M the dark trailing overshoot is quite apparent.

 

27" 6ms G2G LG.Display AH-IPS

24" 2ms G2G AU Optronics TN Film + 120Hz (AMA = On)

27" 1ms G2G Chi Mei Innolux TN Film + 120Hz (Over Drive = 0)

22" 3ms G2G Samsung TN Film + 120Hz

We've also included a comparison above against three very fast 120Hz compatible screens we have tested. In all cases these other screens are using TN Film panels and are aimed primarily at gamers. Firstly there is a comparison against the BenQ XL2420T. This showed very low levels of motion blur, but some dark overshoot was introduced as a side-effect. The Iiyama G2773HS was very responsive and even has a quoted 1ms G2G response time. This showed very low levels of blur and had minimal issue with overshoot. The Samsung SM2233RZ performed very well in these tests and showed very low levels of motion blur also. When 120Hz mode was enabled the overdrive artefacts evident in 60Hz mode were almost completely eliminated, which is something we have seen with the BenQ XL2420T as well.

While these pixel response tests show the U2713H to have pretty fast transitions and low levels of motion blur, there is something else going on as well here which can't be picked out by the camera. All of these other TN Film models are running at 120Hz refresh rates, which allows for improved 120fps frame rates and the support of 3D stereoscopic content as well. This can really help improve smoothness and the overall gaming experience so these screens still have the edge when it comes to fast gaming. From a pixel response point of view the U2413 performed well, although the overshoot in certain transitions was severe. There are some other areas you still need to think about when it comes to high end gaming. It couldn't keep up with the very fast TN Film models with 120Hz support.
 

The responsiveness of the U2713H was pretty good overall. We had measured a pretty low average G2G response time of 7.2ms which was good, although we'd seen some high overshoot in certain transitions, especially when changing from dark to very bright / white shades. In practice it didn't feel quite as fast overall as the U2713HM model or some of the other popular PLS-based models we've tested. Keep in mind though that this is aimed at higher end uses and the semi-professional market and so the performance for gaming is obviously not a number 1 priority for Dell. It should still be perfectly adequate for most gaming, but those wanting to play fast FPS or competitive games may want to consider some of the more mainstream (and more suitable) models available, or better still, some of the 120Hz compatible displays out there.

On another note many gamers like to use exaggerated settings to make colours look brighter and more vivid. Wide gamut screens can serve this purpose well as they natively produces more saturated colours. This might not be strictly accurate but a lot of people prefer this more vivid and cartoony appearance and so it's useful that the option is available from the U2713H. Of course if you want to revert to a standard gamut you can always switch to the sRGB mode too.

Additional Gaming Features

Aspect Ratio Control - The screen offers four options within the OSD menu for hardware level aspect ratio control. There are options to maintain the aspect ratio at 'wide 16:9' or 4:3 which users will hopefully be familiar with. These will help maintain those specific aspect ratios for certain sources, stretching the image to fill as much of the screen as possible and using black borders to cover the sides (for 4:3 mode). There is also then an option for 'auto resize' which retains the source aspect ratio no matter what it is, and fills as much of the screen as possible (black borders used where needed). This is particularly useful as it will automatically detect the aspect ratio and maintain it. This wasn't available on the U2713HM and so some aspect ratios such as 16:10 could not be maintained at a hardware level. The U2713HM only had options for 16:9, 5:4 and 4:3 so anything other than those would not be handled by the screen. In the case of the new U2713H this is handled via the 'auto resize' option without problem. The last option is for 1:1 pixel mapping which directly maps the source resolution to fill only the required number of pixels. Again handy for those wanting to maintain any source resolution and aspect ratio, without stretching the image at all.

Preset Modes - There is a 'game' preset mode available from within the preset mode menu. This seems to look quite similar to the standard preset mode and it gives you access to the dynamic contrast ratio if you want to use it, not that it really does anything in practice based on our tests. This mode might be useful if you want to set up a specific mode to be different to your day to day normal use profile as well.

 

Input Lag

We have written an in depth article about input lag and the various measurement techniques which are used to evaluate this aspect of a display. We have improved our method by adopting the SMTT 2 (now version 2.5.1) tool which is used to generate the results below. Please see our full input lag testing article for all the details.

Input Lag Classification

To help in this section we will also introduce a broader classification system for these results to help categorise each screen as one of the following levels:

• Class 1) Less than 16ms / 1 frame lag - should be fine for gamers, even at high levels

• Class 2) A lag of 16 - 32ms / One to two frames - moderate lag but should be fine for many gamers. Caution advised for serious gaming and FPS

• Class 3) A lag of more than 32ms / more than 2 frames - Some noticeable lag in daily usage, not suitable for high end gaming

For the full reviews of the models compared here and the dates they were written (and when screens were approximately released to the market), please see our full reviews index.

We have provided a comparison above against other models we have tested to give an indication between screens. The Dell U2713H showed an average total display lag of 25.3ms during this test, ranging up to 31ms maximum. Remember, this represents a signal processing lag along with an element of pixel response time and gives you an idea of the overall delay of the image compared with a traditional CRT screen. This lag was not too severe, but a bit higher than we had seen from some other recent screens, and represented a lag of just over 1.5 frames. The lag of this screen has been categorised as CLASS 2 as detailed above and may be a little high for some very high end gaming. This was slightly slower overall than the U2713HM (also tested using the same SMTT method).

Updated 31 January 2013

In fact we can now calculate more accurately the signal processing lag of the display based on a measurement of the response time using the oscilloscope. The average grey to grey response time was 7.2ms so by subtracting half of this (3.6ms) from the total display lag measured of 25.3ms average we can calculate that the signal processing lag should be ~21.7ms.

We tested the screen in different preset modes including the 'game' option in case there was any bypassing of any internal electronics going on to help improve input lag. Unfortunately there was not and the overall lag remained the same in each mode.
 

 

Movies and Video

The following summarises the screens performance in video applications:

• 27" screen size makes it a reasonable option for an all-in-one multimedia screen, but being quite a bit smaller than modern LCD TV's of course. As far as desktop monitors go it is at the large end.

• 16:9 aspect ratio is more well suited to videos than a 16:10 format screen, leaving smaller borders on DVD's and wide screen content.

• 2560 x 1440 resolution can support full 1080 HD resolution content easily

• The native screen resolution means that some source inputs (especially external devices) will need to be scaled to fill the screen as many will be standard 1080 HD resolution (1920 x 1080).

• Digital interfaces supports HDCP for any encrypted and protected content

• Good to see that both DVI and DisplayPort are provided on this model, allowing you to connect your PC over DVI, and leave the DisplayPort free for an external device potentially. Also good to see HDMI included as that is very popular and widely used for external DVD and Blu-ray players.

• DVI and DisplayPort > Mini DisplayPort cables included in the box, but no "normal" DisplayPort or HDMI cables included

• Light AG coating does not cause issues with reflections which glossy coatings can

• Wide brightness range adjustment possible from the display, including high maximum luminance of ~301 cd/m² and a good minimum luminance of ~58 cd/m². This should afford you very good control for different lighting conditions.

• Black depth and contrast ratio are good for an IPS panel at 800:1 after calibration. Shadow detail in darker scenes should not be lost

• Dynamic contrast ratio available but does pretty much nothing on this model

• 'Movie' preset mode available but impacts contrast ratio a lot so should probably be avoided

• Wide colour gamut available from the backlighting system, so those who prefer brighter and more vivid colours for movies and videos can switch to the native gamut mode and benefit. sRGB emulation also available if you prefer standard gamut appearance.

• Good pixel responsiveness which should be able to handle fast moving scenes in movies without issue.

• Very good range of hardware aspect ratio options which should be able to scale and handle external devices easily. Nice to see an "auto" mode and 1:1 pixel mapping included

• Wide viewing angles thanks to IPS panel technology meaning several people could view the screen at once comfortable and from a whole host of different angles. On darker content the IPS white glow may present a bit of a problem if viewed from wider angles

• Good range of ergonomic adjustments available from the stand. Should be easy to obtain a comfortable position for multiple users or if you want to sit further away from the screen for movie viewing.

• No noticeable backlight leakage, and none from the edges which is good. This type of leakage may prove an issue when watching movies where black borders are present but it is not a problem here.

• No integrated stereo speakers on this model or audio connections but it is compatible with Dell's SoundBar.

• Picture in picture (PiP) and Picture By Picture (PbP) available if needed.

• For PAL sources, we have tested the screen and confirmed it will support the full native resolution of 2560 x 1440 at 50Hz refresh rate.
   

Smart Video Enhance

This is a new feature we've not seen on other Dell screens before. The feature automatically detects video (motion) in any window on the screen, and applies enhancements to the video. Only the video window is enhanced. Two different enhancement settings are available as well, those being "Movie"- suitable for movie or multimedia video clips, and "Advance" - User adjustable setting. This setting basically features tweaked (or customisable in the case of the "advance" option) settings for contrast, sharpness, offset, hue and saturation. It is designed to only impact video content on the screen so may be a useful feature to some, if you want to change the appearance of your video windows without impacting on the overall screen appearance.

 

Dell U2711 and U2713HM Comparison

 

I know many people are going to be asking the question: "which is better, the old U2711 or the newer U2713HM and U2713H models?" The U2711 is going end of life now to be replaced by the U2713H, which will then run along-side the U2713HM. The distinction really is between a higher end semi-professional use monitor (U2711 and now U2713H) and a more mainstream, multimedia orientated model (U2713HM). This really does make them quite different to one another but we will try and provide a comparison of the three models here to help. I won't compare the various specs as they are not really relevant in practice and I'll look instead at the performance comparison based on our tests:

 

 

Dell U2711 vs. U2713H vs. U2713HM Comparison

 

 

Colour Space

 

Probably the main difference between these three 27" models is the colour space support. The U2711 and U2713H use wide gamut backlighting types (WCG-CCFL and GB-LED respectively) which offer an extended gamut covering 102 - 103% of the NTSC colour space. This can also cover the Adobe RGB reference space as a result and extends considerably beyond the sRGB reference which is still widely used. The support of wide gamut is great if you have a practical use for it and are working with wide gamut content or want to match the Adobe RGB space properly. However, if you are working just with sRGB content, viewing it on a wide gamut screen can lead to issues of over-saturation and neon appearing colours and is difficult to manage for many users. Thankfully both screens include an sRGB emulation mode which is useful in those circumstances.

 

The U2713HM on the other hand uses modern White-LED backlighting which can only cover the sRGB reference colour space, offering >99% coverage according to the spec. It would be referred to as a standard gamut screen. This is therefore easy and practical if you are just working with standard gamut content, but obviously of no use if you need to work in a wider colour space as it cannot support it at all. The added sRGB emulation mode is a nice extra as it very closely matches the sRGB reference space, cutting back on any slight over-coverage from the native gamut.

 

The U2711/U2713H is perhaps more useful to colour enthusiasts, photographers and designers thanks to its wide gamut support, but for the general consumer, most will not need to use wide gamut and will only be concerned with the appearance of standard gamut (sRGB) content. As such they would not want the over-saturated colours and issues associated with trying to manage standard gamut on a wide gamut screen, and so a W-LED based model like the U2713HM is more readily accessible to the average user. The U2713HM is also a fair bit cheaper than the U2713H so a decision regarding whether you truly need or want wide gamut may play a big part here.

 

Colour Depth

 

I'll also make reference to the fact that the U2711 and U2713H feature an 8-bit + A-FRC panel which can offer a colour palette of 1.07 billion colours if you have a relevant end to end 10-bit workflow (application, operating system, graphics card, interface etc). That is very rare and so to 99% of users this support of "10-bit" is largely irrelevant. It's 12-bit / 14-bit internal processing is designed to help improve gradients and signal processing as well. These kind of features are usually reserved for high end graphics screens such as the NEC PA series, but Dell included them here on the U2711/U2713H as well. The U2713HM uses only a normal 8-bit IPS panel and has 8-bit signal processing. This is more than adequate for most users, especially given the aforementioned complexities with achieving a 10-bit workflow. If you do have such a workflow and want support of 10-bit content then the U2711/U2713H would be a more suitable choice. I suspect many people just won't need it. Again the extra cost of the U2713H is related to this 10-bit support.

 

Features and Specs

 

The U2713HM is missing a few of the extra features found on the other two models like the card reader, DisplayPort cable and touch sensitive buttons. The U2713HM does offer the latest generation USB 3.0 ports though while the U2711 was only v2.0. Dell have stuck with USB 3.0 as well on the newer U2713H. The stand on the newer U2713HM / U2713H models also offers a rotate function which wasn't present on the old style stand for the U2711. The move to a LED backlighting units also brings about energy and environmental benefits compared with the older CCFL unit and helps offer a thinner screen profile. One final thing to note is that the new U2713HM and U2713H use a light AG coating and so do not suffer from the grainy, dirty appearance in some uses that the heavy AG coating of the U2711 had.

 

Performance

 

I've included a table summarising these screens side by side based on the testing we have carried out and on my opinions. The screens are colour marked as green (winner), amber (second place) or red (loser) in each category which should be self explanatory. Where I was not able to separate the two they are shown in grey. I will justify each result below:

 

• Approximate price - at the time of publication the new U2713H is ~£108 more expensive than the U2713HM. This is logical as it features some higher end extras and is more aimed at professional users than the mainstream U2713HM. The old U2711 sits in between but is due to go EOL soon.

• Features - The U2713H wins here as it's retained some of the extras of the U2711 (card reader, touch sensitive buttons) but has added a few extras like USB 3.0 support, daisy chaining, hardware calibration, rotate adjustment etc. The U2711 and U2713HM I have marked level here as while the U2711 does have a card reader and composite and component inputs, the U2713HM has USB 3.0 and a rotate function. I suppose really the value of these features depends on what you're looking for from your screen and what you need.

• Screen coating - The new U2713H and U2713HM have a light AG coating and so do not suffer from a dirty, grainy appearance that the heavy AG coating on the U2711 can bring. A definite positive for the new 2013 generation screens. I've marked the U2713H as being slightly ahead since it is free from the "cross-hatching" that some people noticed on the U2713HM.

• Interfaces - The U2711 and U2713H are ahead of the U2713HM here, but go about it slightly differently. The U2711 had D-sub, composite and component inputs and an additional DVI, but arguably most of those are "old" requirements now and probably rarely used. The U2713H instead offers a Mini DisplayPort connection and daisy chaining capabilities via DisplayPort which are probably more useful for the modern market. Both are a little ahead of the U2713HM which didn't offer composite, component or Mini DisplayPort / Daisy Chaining.

• sRGB colour support - Being W-LED based the U2713HM is a native standard gamut screen and so its use with sRGB content is simpler than the U2711 / U2713HM probably for most users. The U2713H and U2713HM carry the more reliable factory calibrations in the sRGB mode which is important to users who might not have other means to calibrate their screens.

• Extended gamut support - The U2711 and U2713H have a wide colour gamut, the U2713HM does not.

• Panel Uniformity - I have marked the U2711 and U2713HM as level in this test. Not much different overall between those samples. The U2713H was more disappointing sadly, showing more variance in luminance across the screen than we'd hoped - although colour uniformity was good. The added uniformity compensation feature seemed to do nothing at all either to improve uniformity, only impact your contrast ratio.

• Office and Windows - There's very little to separate them here although I've marked the U2713H and U2713HM as more suitable thanks to the lighter AG coating and the fact that they don't use PWM to dim the backlight. The U2713H perhaps has the slight edge as it's free from the "cross-hatching" issue some people noticed on the U2713HM and also features a handy card reader.

• Viewing angles - No real separation here

• Movies Overall - The U2711 and U2713H have more video connections which some users might need, but the contrast ratio on the older U2711 was not great. The newer U2713HM and U2713H have a better black depth and contrast ratio so overall the U2713H is the best of both worlds.

• Responsiveness - The U2713HM holds the advantage here as it seemed to have less blur in practice and only a slight overshoot. The U2713H was a little slower but had some overshoot problems in certain transitions. The older U2711 suffered from more noticeable overshoot artefacts in practice however.

• Input lag - hard to accurately compare since the U2711 was only tested using the old stopwatch method. I've provided the figures for reference but keep in mind the U2713HM and U2713H are far more accurate than the old U2711 measurement.

• Black depth - If you are able to use the hardware calibration and are comfortable using the monitors full native gamut you can achieve the best figure on the new U2713H. We reached 0.13 after calibration in this way. The U2713HM was only slightly behind with a calibrated black depth of 0.14, compared with 0.18 on the U2711. A nice improvement made with the newer models.

• Calibrated Static Contrast Ratio - Again, if you are able to use the hardware calibration and are comfortable using the monitors full native gamut you can achieve the best figure on the new U2713H. We reached 964:1 using that method but it was lower if you need to emulate Adobe RGB or sRGB or can only use software methods it seemed. With a static number of 869:1, the U2713HM is not far behind. The U2711 only managed 672:1.

• Dynamic Contrast Ratio - None worked very well at all, although the 1188:1 offered by the U2713HM was higher than the 865:1 of the U2713H and the 759:1 of the U2711.

 

Overall the U2713H felt like a worthy successor to the popular U2711. There's been some positive changes made including a much lighter AG coating, a PWM-free backlight system, hardware calibration support, USB 3.0 inclusion, an improved black depth and improved contrast ratio. Thankfully Dell have not cut corners and have kept some of the premium features from the old U2711 as well with touch sensitive buttons, a wide colour gamut backlight, 10-bit colour depth and even the integrated card reader. Dell may have done away with a couple of things like the composite, component and D-sub connections but in today's market they're not really missed and are easily out-weighed by the new things they've added instead. The replacement of the U2711 is certainly justified we think. Of course this is still aimed more at professional users and so carries a higher price point than some of the more mainstream models out there, but the extra features justify that price point well, and to be fair it's very competitively priced.

 

The more mainstream U2713HM will be available along side the U2713H and still fits a niche well. It may not have the wide gamut  backlight, 10-bit colour depth or the hardware calibration support, but then many users just don't need (or even want) those anyway. It still brings you a really good range of connections and features and unless you specifically need the extras of the U2713H, still makes an excellent choice for your average user.

 

 

Conclusion

This has been a very extensive review and we've had a lot of time to test the new U2713H fully. As we've said in the previous section the U2713H seems a very worthy replacement to the U2711 and a great alternative to run along-side the U2713HM which still has it's place. We won't repeat all of those points again here but please read the comparison section above for more information and importantly to help you understand where the differences are.

We were impressed by many aspects of the U2713H during our testing. It was great to see Dell have again gone with a light AG coated panel as they had surprised us with when we tested the U2713HM. The PWM-free backlight system was also positive and the re-appearance of the card reader was welcome. We liked some of the new additions like the USB 3.0 hub, Mini DisplayPort connection and support for hardware calibration. On that note, while we were pleased to see this high end feature available, we were pretty disappointed by the very inflexible nature of the solution. The software was free which is great, but did seem pretty basic and lacking of many options and reporting functionality. The more pressing issue was the lack of support for any calibration devices other than X-rite's i1 Display Pro. If you don't have a device already and are buying one to go with this screen that might not be a problem, but for anyone who has already spent a reasonable amount of money on a tool will be frustrated by this. We'd really like to see Dell / X-rite open up the options here to allow more flexible hardware calibration. Having had chance to test the hardware calibration later on after the original review was published we are pretty pleased with the results really and you can at least include a colour space emulation if you need to.

Another feature which left us disappointed was the uniformity compensation. We felt the luminance variation across the screen was not great, on our sample at least. The compensation technology seemed to do nothing at all and Dell haven't quite got that nailed on this first attempt we don't think. We were pleased on the other hand that there was no obvious backlight bleeding and the colour uniformity was good across the screen.

The response time of the screen was pretty good, and thankfully some of the issues with overshoot which appeared on the U2711 have been cleared up. However in certain transitions our new response time testing approach revealed some quite high RTC overshoot. Input lag remained at a similar mediocre level to the U2713HM so this isn't an ideal gaming screen, but then that's not really the market anyway. For the colour enthusiast the wide gamut support, reliable Adobe RGB and sRGB emulations, decent factory calibration modes and 10-bit support are very useful and welcome. If the hardware calibration had been a bit more flexible and the uniformity compensation had worked properly this could have been a very interesting competitor to the likes of the NEC PA series and ranges from Eizo. As it is, it falls a little short of being a truly high end professional screen, but given its retail price is ~£300 less than something like the NEC PA271W it is still an interesting alternative. It carries some of the performance features you might want and certainly delivers with a wide range of connections, adjustments and extra features. Another very good screen from Dell and well worth considering if you want something high end, but at a very reasonable cost.