Introduction

It seems in recent months we've had a flood of new 27" models into the market from various places. What makes this particularly interesting though is that these are all low cost IPS based screens, offering a very interesting alternative to the popular mainstream models out there like the Dell and Apple screens. Hazro did something similar in early 2011 with their Hazro HZ27WA/C models (and now the replacement Hazro HZ27WD), finally offering consumers something they'd been requesting for a long time. A screen which offered them 27" size, a massive 2560 x 1440 resolution, the benefits of the popular IPS panel technology, the increasingly popular W-LED backlighting, a glossy panel coating and a standard colour gamut. All of this for a very competitive price. The Hazro models were available mainly in the UK although some people started to import them to other locations including the US.

More recently in March 2012 we spoke about the wide range of Korean manufactured screens which seemed to be offering the same kind of deal. Very low costs, and a wide selection of different options and extras, depending on which model you went for. Models emerged from manufacturers like Achieva Shimian and Yamakasi for instance, but what they all had in common really was the use of an LG.Display IPS panel. These models are not officially available in any US or UK store, but were imported by many people from eBay sellers, attracted by the low costs and seemingly decent reports of performance and the range of options and extras they had on offer. There were of course some big limitations with buying screens in this way imported from Korea, as it was identified that the manufacturers were often using lower grade panels, and warranties were hard to support internationally. While there were some questions in these areas, many people continued to purchase the screens and were happy with the products they received.

In the UK another option has emerged for people wanting something similar. Digimate (aka DGM) have now released their new DGM IPS-2701WPH model. Following the same principle as these other screens discussed here, it is a low cost offering with a 27" 2560 x 1440 resolution IPS panel. The screen has a wide range of connectivity options and a glossy screen coating and so is already attracting a lot of interest. It is available in the UK exclusively from Overclockers.co.uk at a very competitive price. Panels are top-end A+ rated from LG.Display and the screen comes with a 3 year warranty through Overclockers, giving consumers piece of mind hopefully.

 

Specifications and Features

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

Manufacturers website link: DGM

The IPS-2701WPH offers a very good range of video and audio connections which is great to see considering it is a lower cost screen. There are HDMI, Dual-link DVI-D, D-sub and DisplayPort provided for video interfaces. With the screen offering a 2560 x 1440 resolution though only the DL-DVI and DisplayPort connections can support the full resolution due to bandwidth limitations over VGA and HDMI. It is nevertheless nice to see VGA and HDMI provided for users who want to connect other devices, particularly external Blu-ray and DVD players. While the spec doesn't mention it, checking the NVIDIA graphics card control panel confirms that the digital interfaces are HDCP certified for encrypted content.

The screen comes packaged with a dual-link DVI and a VGA cable which is good to see, and an audio cable for connecting from PC into the back of the monitor is also provided. This would then allow you to use the integrated stereo speakers, which are also able to play sound from the HDMI and DisplayPort inputs if applicable. Note that no DisplayPort or HDMI cable is provided with the screen. The screen has an external power brick which is provided in the box. Sadly there are no other extras such as USB ports which are often very useful I think but we can't grumble really at the video connections here.

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

OSD Menu

 
Above: view of OSD operational buttons

The OSD menu and screen are controlled using a set of 7 buttons located on the bottom edge of the screen in the right hand corner. These are then labelled on the bezel as shown above, telling you what each button will do. The far right button underneath is the power on/off button and the small round button on the front of the screen does nothing.

The buttons give you quick access to a few features. The 'auto' button actually gives you quick access to the input select which admittedly I missed the first time around, but is useful to have available for quick switching. 'Menu' obviously pops up the full OSD menu which we will look at in a moment. The 'Vol+' and 'Vol-' buttons give you quick access to the adjustment of the speaker volume which is useful. This pops up a small box in the middle of the screen as shown above, allowing you to control the slider easily.

The 'up' button by default gives you quick access to the range of so-called 'ECO modes', which are basically a series of 4 presets. These pop up a small graphic in the middle of the screen showing you are switching between text, movie, game and standard modes.

The 'down' button gives you quick access to the DCR (dynamic contrast ratio) function, again allowing you to turn this on and off, aided by a small graphic in the middle of the screen. You can actually change the options for these quick launch buttons if you want from within the main OSD. The only other options though are ECO modes + aspect ratio control and brightness + contrast controls.

 

The main OSD menu is a fairly nice looking bit of software which is split into 6 sections down the left hand side. Navigation between these is achieved using the up and down buttons and the menu button enters you into a section and then selects one of the options. The text turns red for the option you are controlling. The only slightly fiddly thing though is that once you have selected an option it is not the up and down arrows which then change the setting, but instead you have to switch over and use the vol+ and vol- buttons. It takes a little getting used to and you do find yourself hopping from button to button, having to feel your way to the right one underneath the bottom edge of the screen.

The first section is labelled as the 'brightness' section, giving you control over the brightness and contrast settings as a starter. You can also control the ECO mode preset selection here and turn the dynamic contrast ratio on and off.

The second section is the 'image' menu, allowing you to control a few features related to the use of the analogue VGA input. They are greyed out here since we are using DL-DVI for testing. You can also control the hardware level aspect ratio retention feature with options for wide and 4:3 available (we will look at these later on). The third section is the 'color temp' menu allowing you to select between 4 colour temperature modes if you want. There is a 'user' setting which then allows you to adjust the RGB channels individually from within this same section.

The fourth section allows you to control the OSD behaviour as shown above, while the fifth section offers options to reset back to defaults.

The sixth and final 'misc' section allows you to control the quick launch options as explained earlier, choose your input source and adjust the volume of the speakers.

There is also a hidden factory menu available from the screen. If you hold 'menu' while turning the screen on you can access this yourself. It pops up a small box in the top left hand corner with red writing confirming firmware and part numbers. This confirms the panel being used as well which is the LG.Display LM270WQ1, as featured in other competing options including the Apple 27" Cinema Display and Hazro HZ27WA/C/D models. If you then press 'menu' the main OSD is mostly the same, except there is now a red label saying "burn in" at the bottom, indicating that the burn in feature is enabled. The menu sections are the same, except that if you scroll up above the 'brightness' section there is a seemingly blank section as shown above. Pressing the 'menu' button again when you are selected on this blank section pops up a more detailed factory menu shown below.

The factory menu confirms various things about the screen and also allows you (if you want to - use entirely at your own risk) to change the colour preset RGB levels and turn the burn-in feature on or off.

All in all the OSD was good I felt. There were a decent range of options, especially considering this is a low cost screen and some alternative competitors have done away with any OSD at all. Navigation was ok, although the switching between the up/down and vol+/vol- buttons could be a bit tricky sometimes.

 

Power Consumption

In terms of power consumption the manufacturers spec states maximum usage of 120W. In standby the screen apparently uses <1.5W.

We tested this ourselves and found that out of the box the screen used 48.3W of power while at its default brightness setting which was 50%. At the maximum brightness setting the screen used 104.2W of power and at the lowest brightness setting, power consumption was reduced to 24.2W. After calibration the brightness had been set at 55% to achieve the desired luminance and this returned a power consumption of 53.9W. In standby the screen used 1.8W of power.

I have plotted the results of these measurements on the graph below:

Panel and Backlighting

The DGM IPS-2701WPH utilises an LG.Display LM270WQ1-SDE3 H-IPS panel which is capable of producing 16.7 million colours with a true 8-bit colour depth. We get asked quite a lot why some places refer to modern IPS panels as "S-IPS" and others use the "H-IPS" name. Have a read of our panel technologies article for more information, but they are just two different types of IPS technology, with the new name being introduced when a change in pixel alignment was introduced some years ago. H-IPS has a straight vertical pixel structure whereas the older S-IPS panels had an arrow shaped structure. This panel used here is based on the straight pixel structure so is technically of the H-IPS classification. Again it should be noted that DGM have confirmed they have selected A+ grade panels for this model. The panel is confirmed below when dismantling the screen.

The IPS-2701WPH uses White-LED (W-LED) backlighting producing a colour space approximately equal to the sRGB reference. This means the screen is considered a 'standard gamut' backlight type. Studying the detailed panel spec sheet confirms that the colour space is equal to 77% of the NTSC space, 77.2% of the Adobe RGB reference and 99.9% of the sRGB space. A wide gamut screen would need to be considered by those wanting to work outside of the sRGB colour space of course.
 

PWM Flicker Tests at Various Backlight Brightness Settings

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 100%, 50% and 0% brightness settings. This allows 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.

Interestingly the DGM IPS-2701WPH appears to not use PWM at all for dimming of the backlight. 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. There are very few monitors which don't use PWM for backlight dimming (the HP ZR2740w springs to mind as another), but this model does not.

 

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:

DGM IPS-2701WPH - Default Factory Settings

   

 

The default set of the screen actually felt very good to the naked eye. Colours felt even and not too cold, not too warm. The brightness was comfortable as well while the screen was set at its default 50% brightness setting. You may note that by default the screen is in the 'normal' colour temperature mode, where the RGB levels are locked at 63, 59 and 51 respectively. You are able to change these levels yourself by entering the 'user' colour temperature mode which we will test in a moment. We left the screen in the default 'standard' ECO preset mode as well.

 

Out of the box the performance of the screen was very pleasing. The CIE diagram on the left confirms that the monitors colour gamut (black triangle) matches the sRGB colour space (orange triangle) reasonably closely. It extends a little past the sRGB space in some blues and reds in particular in this 2D view of gamut which fits in with the fact we know it can cover ~77% of the NTSC colour space, and so extends beyond sRGB slightly. There is pretty much no under-coverage of the sRGB reference space and we know from the panel spec that it can cover 99.9% of the sRGB reference which is great.

 

 

Default gamma was recorded at 2.2 average, leaving it only 1% out from the target of 2.2 which was great. The gamma was a little too high in darker grey tones where it ranged up to 2.33 maximum. Still, a good default gamma setup from the screen which was good news. White point was also very close to the target, being recorded at 6439k and being only 1% out. Note that we are using a spectrophotometer to make these measurements which is not sensitive to the W-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, 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 modest and comfortable 109 cd/m² which is fine for general use. The black depth was a fairly poor 0.19 cd/m² however, giving us a mediocre static contrast ratio of only 518:1. This was behind some other modern IPS based screens we have tested. We will see if it is possible to improve on this in a moment during our calibration process. Colour accuracy was pretty good at default factory settings with an average DeltaE (dE) of 2.4, ranging up to a maximum of 5.3. Along with the good gamma and white point, this factory setup was very good really, especially considering the low cost of the screen. The only area we were disappointed with was the black depth / contrast ratio however.

 

 

Testing Colour Temperatures

 

 

The IPS-2701WPH features a range of colour temperature presets within the OSD 'Color temp' menu as shown above. 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 labelled in words as opposed to specific figures. We had already seen that the 'normal' setting had returned a colour temperature very close (within 1%) to the 6500k target in our tests which was great news. The cool setting was indeed cooler at 8594k while the warm setting was warmer at 5612k. The user setting was very cool by default, where the RGB channels were at their default 100, 100, 100 levels. Changing those RGB channels will alter the colour temperature but does afford you a decent level of control over the hardware itself.

 

 

Calibration Results

 

I wanted to calibrate and profile the screen to determine what was possible with optimum settings and profiling. I 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.

DGM IPS-2701WPH - Calibrated Settings

Monitor OSD Option	Calibrated Settings
Brightness	55
Contrast	60
RGB Channels	100, 85, 75
Color Temperature	User
ECO Preset mode	Standard

	Calibrated Settings
luminance (cd/m2)	120
Black Point (cd/m2)	0.25
Contrast Ratio	475:1

 

I first of all reverted to the 'user' mode in the color temp section of the OSD menu which would allow me access to the individual RGB channels. Adjustments were also made during the process to the brightness and contrast controls, 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. After this I let the software carry out the LUT adjustments and create an ICC profile. The screen does not feature a hardware LUT calibration option so other than the OSD alterations, the rest of the process is carried out at a graphics card level in profiling the screen.

 

We already knew from our colour temperature tests that the user mode by default was far too cool, which is why there is a big drop in the green and blue channels needed in the OSD. The calibration was a great success in most cases.

 

Average gamma had been corrected to 2.2 with 0% deviance according to the initial test. Checking the more detailed table shown above, the average gamma was actually 2.18, so it was rounded up to 2.2 in the first report. Gamma was slightly closer to 2.2 in the darker shades than in the light greys but overall the gamma curve was good. White point had been maintained at within 1% of the target, now measured at 6537k. Luminance was now spot on at 120 cd/m² thanks to the adjustment of the brightness and contrast controls as shown. This gave us a fairly weak black level however of 0.25 cd/m², and a resulting calibrated static contrast ratio of 475:1. We tried several different options to see if it was possible to improve this through changes to the RGB channels and contrast control, but we didn't have much luck. This did seem to be a weak point of this screen. Having said that, subjectively the blacks looked good to the naked eye as the glossy screen coating did make them 'pop' and look deep. In reality though the contrast ratio was not as good as other IPS panels we have seen which can reach up to ~1000:1 in some cases. Colour accuracy was improved nicely though with dE average now only 0.4, and maximum 1.3. LaCie would consider colour fidelity to be excellent overall.

 

Testing the screen with various colour gradients showed mostly very smooth transitions. There was some 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 most other IPS panels, this screen does not feature the usual grainy and dirty looking Anti-glare (AG) coating. Instead it uses a glossy screen coating and as a result the colours look very clean and crisp, the image quality is sharp and whites in particular look a lot more pure than they do on heavy AG coated screens. Glossy coating isn't to everyone's taste though as it can introduce reflections which are annoying. You should probably try and see a glossy and an AG panel in person if you are unsure what to buy.

 

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.

 

 

 

Calibration Performance Comparisons

 

 

I've provided a comparison above of the IPS-2701WPH against some of the other screens we have tested. Out of the box average dE was 2.4 which was pretty decent really and combined with the good default gamma, white point and luminance represented a good factory calibration. It offered a similar level of accuracy to the HP ZR2740w (2.2) which is another 27" IPS + W-LED model and was also quite close to the Hazro HZ27WC model (dE 1.5 average) which is its closest rival in the UK really. The Hazro HZ27WC also had a good factory setup in terms of gamma and white point, although it was a little too bright out of the box. It seems even though the HZ27WC and this IPS-2701WPH are low cost options, their initial setup is good.

 

All these screens were ahead of some of the other 27" models like the AMVA based BenQ EW2730V (6.5) for instance and the PLS based Samsung S27A850D (3.6). The professional grade 27" NEC PA271W and SpectraView Reference 271 were better thought as you might expect at 1.1 dE and 1.5 dE average respectively.

 

 

Once calibrated the dE average was reduced to 0.4. This would be classified as excellent colour fidelity by LaCie. It was not quite as low as some of the other screens here which reached down to 0.2 average, but in practice you would not notice any difference here. Some of the professional range models from NEC are even more accurate. Professional grade monitors like the NEC PA series and P241W also offer other high end features which separate them from some of these other models, including extended internal processing, 3D LUT's and hardware calibration. These comparisons are based on a small selection of tests, so it should be remembered that other factors do come into play when you start talking about professional use. For further information and tests of a high end professional grade screen with hardware LUT calibration, you may want to have a read of our NEC SpectraView Reference 271 review.

 

 

 

 

The calibrated black depth and contrast ratio of the IPS-2701WPH were a little disappointing really and this is probably the main weakness of the panel. Black depth was only 0.25 cd/m² after calibration and this gave us a static contrast ratio of 475:1. This was not very good for a modern IPS panel and we have seen figures of up to ~1000:1 in some cases. Some other IPS based 27" models are also not great in this area, such as the Dell U2711 (672:1) and NEC PA271W (600:1) but even so we would have hoped for a little more than 475:1 from the DGM. Having said that, because of the glossy screen coating, the blacks do look and feel pretty good and subjectively the contrast doesn't look too bad.

 

 

Contrast Stability

 

The luminance range of the screen was very wide indeed. At a maximum brightness setting the screen reached 291.6 cd/m² which was a little shy of the specified 350 cd/m² maximum. This could be adjusted all the way down to a very low 11.9 cd/m² through changes to the brightness control, giving you a 279.7 cd/m² adjustment range. Black depth ranged from 0.52 to 0.02 cd/m² but the overall static contrast ratio was on average ~544:1 which wasn't great unfortunately.

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 isn't a linear relationship though as the top 50% of the adjustment range seems to make steeper changes to the luminance than the bottom 50% of the range.

Static contrast ratio was not great, with an average of 544:1. This was fairly stable across the range, but did seem to be slightly higher between a setting of 40 - 0%.

 

Dynamic Contrast

We tested the DCR feature and you could immediately notice the screen getting much brighter when you first turn it on. In fact on an almost all-white screen the luminance reached up to 329.4 cd/m² which was even a bit higher than we'd seen through the normal brightness controls. However, switching to an almost all-black screen didn't seem to do anything and the screen appearance did not change. We measured black depth at 0.52 cd/m² and so the dynamic contrast ratio being produced was only 634:1. We tested the screen again with a completely 100% all-black screen and you could see (by having the OSD menu open) that the backlight was now being controlled and it took about 3 seconds to change from maximum to minimum brightness. It looks like another screen where the feature can work to a degree, but only in the most unrealistic and extreme circumstances which you will probably never experience in real use.

Unlike some models from Asus and LG however we did not see the backlight being turned completely off and so what you are basically doing is controlling the full range of the backlight intensity in the space of around 3 seconds. In real use you are never going to have a 100% black screen so the use of this feature is very questionable. If it did operate under less extreme circumstances you could in theory get a maximum luminance of 329.4 cd/m² and a minimum black level of probably around 0.02 cd/m². That black depth figure is taken from our contrast stability section and would in theory give you a dynamic contrast ratio of ~16,500:1. That would be a fairly reasonable figure and may be of use to some people at least. The screen would never live up to its 80,000:1 spec though as you would have to be turning the backlight off to reach a lower black point than 0.02 cd/m² it seems. In fact it would be then tending towards infinity:1 if you consider its black point is basically then 0 cd/m² if that did happen. However, in practice you are never going to be able to see a DCR range like that. In fact in normal use the DCR doesn't seem to operate at all. Another marketing gimmick and a disappointing trend we've seen from a lot of other screens.

We would like to start seeing realistic DCR figures being quoted from manufacturer really, not made up numbers which don't translate into real performance. I'd rather see a screen with a useable DCR of ~10,000:1 for example than a screen with an advertised 100 million:1 which only works in the most extreme and unrealistic circumstances that a user will never see.

 

Viewing Angles

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

Viewing angles of the IPS-2701WPH 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 did offer 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.

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 too much of a 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. This is accentuated a little due to the sheer size of the 27" panel. 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. That is a little difficult to explain but hopefully makes sense. It is only really apparent on darker content and only really if you are working in darkened lighting conditions on this model. It was not too severe I didn't think, but something to be aware of.

Panel Uniformity

Measurements of the screens 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 above 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.

Uniformity of Luminance

The luminance uniformity of the IPS-2701WPH was very good overall. There was some slight variance in luminance, particularly along the bottom edge but only by about -19% in the most extreme cases. Along this edge the luminance ranged down to 101 cd/m² but the central regions of the screen were much closer to the target 120 cd/m² and within ~5% on the most part. Approximately two thirds of the screen was within 10% deviance of the 120 cd/m² central point which was good.

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. To the naked eye, there did not appear to be much in the way of backlight leakage although you could notice the characteristic IPS-glow as you looked at the black image from different angles. The camera picked out some slight unevenness and some clouding from the backlight in the corners. This was most apparent in the bottom right hand corner but in practice overall there was nothing too severe. There was no bleeding from the edges which was good to see as that can become quite distracting during some uses, for instance when watching a movie with black borders top and bottom.

General and Office Applications

The IPS-2701WPH features a massive 2560 x 1440 WQHD resolution which is only just a little bit less vertically than a 30" screen. The pixel pitch of 0.233mm 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 res 27" models offer the tightest pixel pitch and therefore the smallest text as well. I don't find it too small personally, but day to day I am used to a 24" screen. 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 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 DGM have opted for the high res panel here rather than sticking with another 1920 x 1200 or 1920 x 1080 res panel as you may find in other older 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. The glossy screen coating ensured that the white backgrounds of office documents looked clean and pure, and did not suffer from the grainy and dirty feel of some IPS panels featuring aggressive AG coating. Being glossy though it did introduce some reflections which were a bit of a pain sometimes. You will want to ensure you don't have the screen facing a window or strong light source I would think.

There were four preset modes available from the 'ECO mode' menu, all of which seemed to be cooler than our calibrated standard profile when at their defaults. They might be useful to some users though and there is a 'text' setting available if you want. The brightness control also allows you to control a huge range of adjustment to the luminance of the screen which is excellent. Even out of the box, the 50% default brightness is comfortable for office use and measured at around 109 cd/m² in our tests. A setting of around 55% should return you a luminance close to 120 cd/m² for office use if you want, and you are able to control the brightness all the way down to around 11 cd/m² at the 0% setting which is excellent. Those wanting to use the screen in low lighting conditions shouldn't have any issue here. 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 stand provided offers limited adjustments unfortunately. The tilt function allows for a reasonable range of angles to get a comfortable setup, but unfortunately there is no height adjustment which might be missed by some people. There is no rotate function either to switch between portrait and landscape modes, but the practicalities of using that on a screen this size are questionable. If you want to, you can wall or arm mount the screen though for improved flexibility. The integrated speakers should be adequate for general office sounds and light music as well. There are no further extras like USB ports or card readers here sadly, but the interface range is very good. With DisplayPort and DL-DVI both supporting the full 2560 x 1440 resolution you should have a decent choice for your PC. Since the VGA input was not able to support the full resolution of the screen we did not compare the sharpness of the image between analogue and digital, but the digital picture quality was excellent.

 

 
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 60Hz refresh rate. If you want to you can run it outside of this and let the image be scaled to fill the screen. At the native resolution text was very sharp and clear. We ran the screen at 1920 x 1080 which was the next step down, while still maintaining the screens 16:9 aspect ratio. Text was actually very good and was hardly blurred at all. The screen is perfectly capable of being run at a lower 1920 x 1080 resolution if you wanted to, without much degradation in the picture quality and sharpness. To give you more desktop real estate and maximum picture quality, the native resolution is of course recommended where possible.

 

Responsiveness and Gaming

The IPS-2701WPH is rated by DGM 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. The panel being used is an LG.Display LM270WQ1-SDE3 H-IPS panel. Unlike quite a lot of screens we have tested recently there is no control over this overdrive impulse from within the OSD, and so you will have to rely on the setup by the manufacturer here.

The screen was tested using the moving car test in PixPerAn for the 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 direct comparison of the impact of this setting:

 

27" 6ms G2G LG.Display H-IPS

27" 6ms G2G LG.Display H-IPS

27" 6ms G2G LG.Display H-IPS

27" 6ms G2G LG.Display H-IPS

27" 12ms G2G LG.Display H-IPS

I have provided a comparison of the IPS-2701WPH first of all against some of the other 27" IPS based screens we have tested. You will see first of all a comparison against the Hazro HZ27WC and HZ27WA which are the closest rivals to the DGM really in the UK. Both are also low cost screens with standard gamut IPS panels and a glossy screen coating. The responsiveness of the IPS-2701WPH was good in practice and the moving image showed no noticeable ghosting. There was a slight blur to the image as you might expect but overall we were pleased with the pixel response times here in this test. It produced very similar results to the Hazro HZ27WC in fact, both with only a feint trail behind the moving car in the photos above. The Hazro HZ27WA had not been quite as good as it had produced a dark overshoot artefact through the slightly too aggressive overdrive impulse. This was even more pronounced on the Dell U2711 in fact, and while these two models did offer low levels of motion blur, they did suffer a little because of this overshoot. The HP ZR2740w was pretty good in these tests as well although a little slower than the IPS-2701WPH with a more noticeable blur.

 

27" 6ms G2G LG.Display H-IPS

27" 5ms G2G Samsung PLS (response time = faster)

27" 6ms G2G AU Optronics AMVA (SmartResponse = Fastest)

27" 8ms G2G AU Optronics AMVA (AMA setting = Premium)

If you then compare the IPS-2701WPH with 3 other 27" screens we have tested which use AMVA or PLS panel technology there are more pronounced differences in some cases. The Samsung S27A850D had impressed us in these tests with its PLS panel technology and with a fast response time and very low levels of motion blur. It remained a little ahead of the IPS-2701WPH in fact. The Philips 273E3QHSB and BenQ EW2730V are based on AMVA panel technology and fell behind in these tests. The generation of AMVA panel being used in those two models was not able to compete with the responsiveness of modern IPS or PLS displays and there were quite high levels of blur evident, even with their response time controls turned up to the optimum levels. Those screens are rated with a 6ms and 8ms G2G response time respectively which just goes to show you can't always trust a specification when determining real life performance of a display.

 

27" 6ms G2G LG.Display H-IPS

24" 6ms G2G LG.Display e-IPS (Video OverDrive = On)

24" 8ms G2G LG.Display e-IPS

23" 8ms G2G LG.Display e-IPS (W-LED)

24" 4ms G2G AU Optronics AMVA (AMA = Premium)

Above is a comparison of the IPS-2701WPH against some popular models in smaller sizes. First are three models using IPS panels, but n smaller sizes of 24" and 23". The HP ZR2440w had performed very well in these tests and showed a lower level of motion blur to the IPS-2701WPH in practice. There was a very slight dark and pale halo trail evident in those tests but it was very slight. The Dell U2412M and U2312HM again offered low levels of motion blur but a more obvious dark overshoot trail was introduced. The larger 27" IPS panel of the IPS-2701WPH was not quite as fast as these smaller IPS screens but was at least free from any dark overshoot. I have also included the results from our recent review of the BenQ GW2450HM since there had been some big improvements made in AMVA panel technology in this most recent generation of panel. Thankfully the responsiveness was much better than we'd seen from the Philips 273E3QHSB and BenQ EW2730V we showed you above and was on par in practice with these IPS screens.

27" 6ms G2G LG.Display H-IPS

27" 1ms G2G CMO TN Film (Response time mode = Advanced)

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

22" 3ms G2G Samsung TN Film + 120Hz

I've also included a comparison above against 3 gamer-orientated screens, including the 27" TN Film based ViewSonic VX2739wm. While it is the same size as the DGM IPS-2701WPH, it is very different of course. That model is aimed primarily at gamers and even has a 1ms G2G quoted response time. It also uses a TN Film panel and so has restrictions in some areas, such as viewing angles. It performs a bit better than the IPS-2701WPH though in these tests as you might hope. It is of course as expected considering it is a gamer-orientated TN Film model.

The other two models here both featuring heavily overdriven TN Film panels, and are combined with 120Hz technology. The pixel responsiveness of both of these is also a little ahead of the IPS-2701WPH, but more importantly the 120Hz frequency allows for improved 120fps frame rates and the support of 3D stereoscopic content as well. The recently tested BenQ XL2420T offers some very fast performance and is a screen purely aimed at gamers. The Samsung 2233RZ arguably remains our champion if we base it purely on the responsiveness tests. Both these screens do perform faster in practice though thanks to their 120Hz support, giving you smoother moving images and higher frame rates.

The responsiveness of the IPS-2701WPH was pleasing we felt. It offered no obvious ghosting and only low levels of motion blur. It could compete easily with the other 27" IPS models we had tested and showed a sharp moving image, free of any noticeable overshoot artefacts which had affected some of its competitors. The screen should be perfectly capable of handling fast paced games, although you may want to consider the type of graphics card required to run games with high settings at such a high resolution. Thankfully we'd also seen good image interpolation at lower resolutions and so gaming with an input resolution of 1920 x 1080 (for instance) is also very viable.

 

Additional Gaming Features

Aspect Ratio Control - The screen offers two options within the OSD menu for hardware level aspect ratio control. There are settings for 'wide' which will fill the whole screen regardless of the input resolution, and for '4:3'. Normally you would expect this mode to force the screen to a 4:3 aspect ratio display, regardless again of the input resolution. In reality it seemed to behave quite differently.

Some resolutions would always be shown full screen, regardless of whether you had set the display to wide or 4:3. For instance a 1920 x 1200 (16:10 aspect) or a 1600 x 1200 resolution (4:3 aspect) seemed to always be stretched to fill the screen. Some other lower 16:10 aspect ratio resolutions such as 1680 x 1050 and 1440 x 900 had black borders down the sides when in 4:3 mode, but the aspect ratio shown was not actually 4:3, it was the 16:10 of the source (always stretched to fill as much of the screen as possible though but maintaining the aspect ratio). Some lower than native 16:9 aspect resolutions like 1600 x 900 would show with black borders down the sides, but would be stretched vertically into a 16:10 aspect ratio. In this example switching to the 'wide' mode would fill the screen and correct the aspect ratio back to 16:9. Other lower resolutions still like 1280 x 1024 was maintained at its native 5:4 aspect ratio while proper 4:3 input resolutions like 1280 x 960 ended up being stretched into 5:4 aspect ratio.

There didn't seem to be a pattern to it really, sometimes the 4:3 mode retained a 16:10 aspect ratio, sometimes it retained a 5:4 aspect ratio, and other times when it should have been supporting a 4:3 aspect, it filled the screen completely or changed it to 5:4! We have produced a table showing these results below for reference. If you do need to run anything outside of the native aspect ratio then be wary of this hardware limitation, or better still, rely on your graphics card  or input device to do the aspect ratio control for you.

 

 

Preset Modes - There is a 'game' preset mode available from within the ECO mode menu. When using these other presets it seems that the brightness and contrast options are greyed out and locked to whatever you had them set at in the 'standard' mode. They also have a defined RGB / colour temperature setup and even changing the colour temperature mode doesn't change anything while you're in the game preset. When you revert back to the standard mode though the changes you have made (e.g. changing the colour temperature setting) have changed. Anyway, there is a game preset mode available if you want and it might be useful as an alternative to how you've set up the standard preset. The dynamic contrast option is available in all the preset modes but in practice it doesn't really work, unless you show a 100% all-black screen which is never really going to happen.

 

Input Lag

We have recently 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 also improved our method by adopting the SMTT 2.0 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.

Our tests here are based on the new format using SMTT 2.0. We have provided a comparison above against other models we have tested to give an indication between screens. However, please note that many of the other screens tested here were using older stopwatch methods and not the SMTT 2.0 tool. For reference, those shown as darker blue lines were tested using SMTT 2.0.

The DGM IPS-2701WPH showed an average display input lag of 28ms during this test, ranging up to 30ms maximum. This was not too severe, but a bit higher than we had seen from some other recent screens, and represented a lag of close to 2 frames. The lag of this screen has been categorised as CLASS 2 as detailed above.

 

Movies and Video

 The following summarises the screens performance in video applications:

• 27" screen size makes it a pretty good option for an all-in-one multimedia screen and comparable to smaller LCD TV's in size. A screen this big really does help lend itself to video viewing.

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

• Native 2560 x 1440 resolution can easily support true 1080 HD content (1920 x 1080 resolution)

• Digital DL-DVI, DisplayPort and HDMI interfaces support HDCP for any encrypted and protected content

• Good to see DisplayPort and HDMI provided for connection of additional devices, both of which are very popular for external DVD and Blu-ray players.

• Glossy screen coating can look attractive but may cause issues with reflections depending on room conditions and light sources. Perhaps not as suitable as an anti-glare coating for this purpose.

• Contrast ratio was not great sadly. It should be ok for movie use and on the most part detail in darker scenes and shadow detail should not be lost but if you are watching a lot of dark content it might cause some issues.

• Dynamic contrast ratio is available but doesn't really work in practice. You have to have a 100% black screen for it to function which is probably never going to happen in real use.

• There is a 'movie' preset mode available in the OSD ECO mode if you want to set up a mode specifically for your movie viewing

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

• 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. The IPS glow from an angle might present a problem on darker content depending on your line or sight and distance from the screen

• Limited ergonomic adjustments available from the stand with only a basic tilt available. Would have been useful to see height adjustment as well.

• No obvious backlight leakage 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. Some slight clouding in the corners which might become evident in darkened room conditions sometimes.

• Integrated stereo speakers available if you want, along with audio pass-through and a headphone socket. Might be useful for the occasional video but of course the speakers aren't up to a great deal.

• No picture in picture (PiP) or picture by picture (PbP) modes available on this model.

 

Conclusion

The DGM-IPS-2701WPH was overall an impressive screen I felt. While the focus has clearly been on offering a low cost IPS high-res screen, they have not sacrificed in too many areas. There is a wide and decent range of video connections available and it's great to see DisplayPort and HDMI included. There are even integrated speakers which are a nice little extra. Default factory setup was very good it seemed with pretty decent colour accuracy and a reliable gamma, white point and luminance setup. The IPS panel offered some very good all-round performance with very wide viewing angles, fast pixel responsiveness and good colour rendering. Of particular note I felt were the very wide range of luminance adjustments from the brightness control with a very low minimum setting for those who like to work in darker conditions. The fact that the screen does not use PWM for backlight dimming should also be seen as a big positive by many and was a pleasant surprise. The 2560 x 1440 resolution IPS panel offered very good picture quality with a sharp image and massive desktop real-estate. The glossy panel coating also meant it was free from the dirty look of some AG-coated IPS models and is bound to be a big plus point to many people.

There were a couple of areas which disappointed us a little however. Black depth and contrast ratio were not the strong point of this panel it seemed and so were a little lacking. The stand was very limited and also quite wobbly but at least you can wall or arm mount the screen easily enough if you want, even if you do need to take the screen apart to do so. We saw another dynamic contrast ratio which didn't function in practice, but that doesn't really surprise us, and there was some IPS glow evident on darker content, accentuated by the size of the screen.

All in all though, the few negatives can be quickly forgotten I think when you consider the very low cost of this screen. At ~�380 GBP in the UK at the moment it is significantly cheaper than some popular 27" models like the Dell U2711 (~�540) and even a little less than the Hazro HZ27WC (�390). In fact when the DGM was first released it was available on pre-order at �319.99 which is a real bargain. At these kind of prices, it's well worth a look as a decent 27" IPS model.