Like the older U2211H, the Dell U2212HM has pressable OSD selection buttons instead of any touch sensitive version. These are located on the right hand side of the screen and work well. The OSD menu itself is pretty much identical to the U2412M and U2312HM.

Pressing any of the 4 buttons brings up the quick launch menu, giving you quick access to preset mode selection and brightness / contrast controls. You can also select to enter into the main menu, or simply exit the quick launch menu. You can in fact personalise the two 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, text, colour temp. and custom colour.

Bringing up the main menu presents you with various sub-sections down the left hand side as shown. At the top right there is a new "energy use" bar which gives you a visual indication of the power consumption at any given time. This was also featured on the U2412M and U2312HM. 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. The auto adjust section is only relevant when using the analogue D-sub connection.

The input source section allows you to manually select which interface is in use, unless you want to use the pretty useful 'auto select' option.

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, 4:3 and 5:4 here. 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. We will look at this later on in the review.

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 access the monitors factory menu as well but be careful not to change anything without knowing what you've done or how to change it back. Use the menu at your own risk! To access the factory menu, hold the top two buttons down while powering the monitor on. Once it is on, press the top button to bring up the menu. You can define the RGB levels for each of the colour temp preset modes here and there are a few other settings relating to the operation of the display. Unlike on the U2412M and U2312HM there is no setting available here for the overdrive ("OD") function which allowed us to control whether the overdrive impulse was turned on or off on the other larger models. We will have to rely on Dell's default setup of this technology when it comes to the response time tests.

Overall the OSD menu offers a decent range of options and it is intuitive and well structured. No issues here.

Power Consumption

Dell's new PowerNap software comes on the CD that shipped with the monitor. This software provides a Power Saving mode for your monitor. The Power Saving mode lets users set the monitor to "Screen Dim" or "Sleep" when your PC enters the screen saver mode.

1. Screen Dim - the monitor dims to a minimum brightness level when the PC is in the screen saver mode.
2. Sleep - the monitor enters the sleep mode when the PC is in the screen saver mode.

In terms of power consumption the manufacturers spec states typical usage of 30W in normal operation and 70W maximum (with Dell Soundbar, maximum luminance and USB active). In standby the screen apparently uses <0.5W.

We tested this ourselves and found that out of the box the screen used 27.9W of power while at its default 75% brightness setting. After calibration, where we had adjusted the brightness control to 38% and therefore the backlight intensity, this was reduced to 21.9W. In standby the screen uses only 0.6W of power. This was quite comparable of course to the other W-LED models we have tested including the U2312HM and U2412M models. I have plotted the results of these measurements on the graph below for comparison:

Colour Accuracy, Black Depth and Contrast

The Panel and Backlighting Unit

The Dell U2212HM utilises an LG.Display LM215WF3-SLC1 e-IPS panel which is capable of producing 16.7 million colours. The panel itself actually uses a 6-bit colour depth with Advanced frame rate control (A-FRC) to produce the 16.7m colours. This is different to regular 8-bit IPS matrices, but this is a measure taken to achieve a lower price point for these modern lower-cost displays. This has been confirmed by Dell.

The U2212HM uses White-LED (W-LED) backlighting. The colour space of this screen is approximately equal to the sRGB reference and is considered a 'standard gamut' backlight type. Studying the detailed panel spec confirms the screen covers 72% of the NTSC reference, 75.2% of the Adobe RGB reference and 97.0% of the sRGB space. As a side note you will see reference on Dell's website of an 82% colour gamut. This refers to the NTSC coverage but is based on a different reference point (CIE1976 = 82%). More common is the CIE1931 standard which would equate to 72% NTSC which is more relevant when comparing with other screens quoting NTSC gamut specs. While a 97.0% coverage of the sRGB space is decent enough and in line with most W-LED backlit screens, some higher end uses may require a wider gamut with a full 100% sRGB coverage (and beyond) for graphics and colour work. A wide gamut screen is another option for those wanting to work outside of the sRGB colour space.

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 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 settings of the screen were as follows:

Dell U2212HM - Default Factory Settings

The out of the box performance of the U2212HM was pretty good really. The CIE diagram on the left confirms that the monitors colour gamut (black triangle) very closely matches the sRGB colour space (orange triangle). It extends a little past the sRGB space in greens in this 2D view of gamut but is a little short in reds.

Default gamma was recorded at 2.1 average, leaving it 4% out from the target of 2.2. Gamma was actually closer to the target 2.2 in the darker greys where it was recorded at 2.23 and 2.18. This deviated as low as 2.04 in other lighter shades however. White point was very close to the target at 6391k which was only 2% out from 6500k. 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 colorimeter with a W-LED backlit screen 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 199 cd/m² which is too high for comfortable use. The OSD is set at 75% brightness and this is too much. At this high 199 cd/m² luminance, the black depth was a very good 0.19 cd/m². This gave us a static contrast ratio of 1039:1 which is excellent for an IPS panel, and only just short of the U2412M (1106:1) out of the box which had impressed us here. It was a little ahead of the U2312HM's default contrast ratio though which had been recorded at 868:1.

Colour accuracy was fairly good at default factory settings with an average DeltaE (dE) of 2.2, ranging up to a maximum of 5.6. The screen felt fairly even to the naked eye but was overly bright and perhaps a little yellow-ish and pale at these default settings. Some minor OSD adjustments to the brightness can hopefully help improve the default set up for casual users who don't have access to a hardware calibration device. To be fair though this kind of out of the box set up should be fine for most casual users anyway, and they can just adjust the brightness control to suit their working environment. It was very similar to the default performance we had seen from the U2412M and U2312HM in fact and all had offered reasonable out of the box performance. The U2212HM here was a little better than the others in fact with all things considered.

Testing Colour Temperatures

Like the 23" and 24" models, the U2212HM features a preset for 'Color Temp' modes. Once selected you are presented with a range of options ranging from 10,000k to 5000k, depending on how cool or warm you want your white point to be. We have already seen that the 'standard' preset mode which is selected out of the box returns a white point / colour temperature of 6391k, which is very close to the target in our tests of 6500k (2% deviance).

We measured the colour temperature of the screen with the X-rite i1 Pro spectrophotometer in each of the preset modes to establish how accurate the settings actually were. All other settings were left at factory defaults and no ICC profile was active. We disabled dynamic contrast ratio as well when testing modes where it became active. The results are recorded below:

As you can see, there is actually a fairly large difference between the requested colour temperature and what is then shown on the screen in most of these 'Color Temp' modes. With the exception of the 6500k mode, each setting was too cold. At the top end, the 9300k and 10,000k settings were very blue in appearance and were 4003 - 5087k too high. The only mode which was pretty close was the 6500k mode, which only deviated by ~65k which was good. Perhaps Dell have spent a bit of time ensuring that this setting is pretty accurate given that it is the most commonly used, but neglected to ensure the other modes are anywhere near the desired colour temperature. The range of colour temp modes of the U2412M and U2312HM had been more accurate when we tested them.

We also measured the colour temperature of each of the named preset modes as shown above. The 'standard' mode was again very close to a 6500k target, being measured here at 6391k (-108k out). The 'movie' mode makes the image a lot cooler, while the other modes are all quite similar to one another at around 6430k.
 

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.

I first of all remained in the default 'standard' preset mode. This preset does not allow you to adjust the individual RGB channels so the only hardware adjustments I would be making potentially are to the brightness and contrast levels. I followed LaCie's calibration process through, adjusting the OSD brightness setting in line with the recommendations made in the process, and then letting the software carry out the LUT adjustments at a graphics card level 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.

The calibration was a success. The gamma discrepancy that we saw before (4%) had been corrected now to leave us with 0% deviance and an average gamma of 2.2. White point was also improved slightly to 6571k, bringing it 1% out from the target of 6500k. Luminance had been reduced to a more comfortable 120 cd/m² after the adjustment of the OSD brightness control to 38%. Black depth was still excellent at 0.12 cd/m² and this gave us a very impressive calibrated static contrast ratio of 1009:1. Colour accuracy was also improved nicely with dE average now only 0.4 and maximum only 0.9. LaCie would consider colour fidelity to be excellent.

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. You may also instead want to use our 'custom color' mode as discussed in the next section.

Dell U2212HM - Calibrated Settings, Custom Color Mode

I switched to the 'Custom Color' preset  mode for this process as it would allow me to change the individual RGB channels. I followed LaCie's calibration process through, adjusting the OSD settings in line with the recommendations made in the process, and then letting the software carry out the LUT adjustments at a graphics card level and create an ICC profile. In this mode I was making further adjustments at the hardware level during the process by changing the RGB channels, which was not possible when profiling the 'standard' mode.

The calibration was again a success. The performance pretty much matched that of our calibrated 'standard' preset with a few of the minor discrepancies improved slightly. The targets were all met well and contrast ratio was retained at a very high 1013:1 which was pleasing. This mode would give you more control over hardware level adjustments and some slight improvement in overall performance as well.

Testing the screen with various colour gradients showed fairly smooth transitions with some slight gradation in darker tones being evident. There was some slight banding in darker tones as well but this was very minimal and only really visible with gradients and not in normal use. There was also some very slight temporal noise evident, particularly in darker tones if you look very closely. This is a result of the FRC algorithm used to produce the 16.7 million colour palette. It's not something you'd notice in practice, and you do have to look very closely to see it. In reality although the panel used is a 6-bit + A-FRC module, there is no noticeable issue with this in terms of colour gradation and performance.

Again, you can use our settings and try our calibrated ICC profile if you wish, which is 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 U2212HM against some of the other screens we have tested in a similar size range. Out of the box average dE was 2.2 on the U2212HM which was very good really. The default colour accuracy of the U2212HM was almost identical to its predecessor, the U2211H (2.3) and also the glossy touch-screen 21.5" Dell ST2220T (2.5). It was also the same out of the box as the 23" U2312HM (2.2) and a bit better than the 24" U2412M (3.2). The professional grade 23" NEC PA231W was better still at 1.3 dE average. A reasonable performance in terms of default colour accuracy from the U2212HM and only a little behind the competition really. Some form of software profiling using a colorimeter would of course be beneficial to correct some of the colours.

Once calibrated the dE average was reduced to 0.3. 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 0.3 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 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 black depth and contrast ratio of the U2212HM were impressive, and thankfully offered the kind of performance we had seen from the 24" U2412M recently. The calibrated black depth of the U2212HM (at 120 cd/m² luminance) was 0.12 cd/m². This gave us a calibrated static contrast ratio of 1013:1 which was actually even a bit higher than the U2412M. In fact the U2212HM was now the champion in terms of static contrast ratios from IPS based models, just edging out the HP ZR2240w which had recently taken the crown at 1005:1. The U2212HM was also ahead of the 23" U2312HM which was pleasing (710:1).

The BenQ EW2420 and Samsung F2380 / NEC EX231Wp with their AMVA and cPVA panels respectively offered some fantastic contrast ratios of ~3000:1 which IPS cannot compete with at the moment.

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.

Contrast Stability

The luminance range of the screen was quite wide with an adjustment range of 193 cd/m² possible. At maximum brightness the luminance was recorded at 247.9 cd/m² which was almost exactly the specified maximum brightness of the panel (250 cd/m²). At the lower end the luminance ranged down to 54.9 cd/m² which should be fine for those wanting to use the screen in low light conditions. Those wanting to use the screen at a luminance of ~120 cd/m² will want to choose a setting of around 35 -40% out of the box to return a comfortable luminance close to this.

Black depth was reduced as one would hope as you lower the brightness control. This ranged from 0.24 cd/m² at the top end down to a very low 0.05 cd/m² at the bottom end.

We have plotted the luminance trend on the graph above which shows a linear relationship. The screen behaves as it should, with a reduction in the backlight intensity controlled by the reduction in the OSD brightness setting.

Static contrast ratio remained pretty even across the adjustment range, with an average figure of 1041:1 which was good. It was a little less stable at the lower end of the brightness range below a setting of ~50%. These contrast measurements were plotted on the graph shown above.

Dynamic Contrast

The tests that we carry out to measure dynamic contrast ratio involve an almost completely white and almost completely black screen. In real use you are very unlikely to ever see a full black or full white screen, and even our tests are an extreme case to be honest. Carrying out the tests in this way does give you a good indication of the screens dynamic contrast ratio in real life situations however.

Like the U2412M and U2312HM, carrying out this test didn't seem to make use of the DCR at all. There was no noticeable change in the backlight intensity when changing between images of different levels of white and black, even when switching between an almost completely white, and an almost completely black image. Watching the OSD menus energy bar also allowed you to see what was being changed and it remained static throughout. Our colorimeter recorded maximum luminance as 246.35 cd/m² and minimum black depth of 0.24 cd/m². This gave us a contrast ratio which was the same as the default static contrast ratio and was recorded at 1026:1. The DCR didn't seem to work at all. Nothing particularly surprising considering some of the DCR performances we have seen from many other models.

However, the feature can work to a degree, but only in the most unrealistic and extreme circumstances. Like the 23 and 24" models if you display an all black screen (completely black) then the feature "works". You can see a change when viewing an all black screen which takes about 3 seconds to happen. This was a quicker change than on the U2412M which had taken ~4.5 seconds to change.

If you bring up the OSD menu and switch to a completely black screen you can see the green energy meter lowering slowly from maximum, to minimum. 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 247.9 cd/m² and a minimum black level of 0.05 cd/m². Those figures are taken from our contrast stability section and would in theory give you a dynamic contrast ratio of ~4958:1. 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 2 million:1 spec though as you would have to be turning the backlight off to reach a lower black point than 0.05 cd/m². In fact it would be then tending towards infinity:1 if you consider its black point is basically then 0 cd/m². 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 this and the other updated Dell screens.

As another note, since the DCR feature is only available in the 'game' and 'movie' preset modes you are limited to the colour temperatures associated with each if you want to use the feature (not that it's of much use!). This presents an additional issue in that the 'movie' preset is very cold, with a colour temp of 11,483k. The 'game' mode is at least pretty close to 6500k, being measured at 6452k.

Viewing Angles

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

Viewing angles of the Dell U2212HM are very good, as you would expect from a screen based on an e-IPS panel. Horizontally there are very wide fields of view with a small contrast shift only really becoming noticeable from a fairly wide angle of about 45�. At more extreme angles the image goes a little darker but in fact this was not as noticeable as on some other e-IPS panels we've tested. Vertically, the contrast shift was more pronounced but the fields of view were still good. The panel is free from any off-centre contrast shift which you see from VA matrices, and this is why IPS technology is so highly regarded in the colour enthusiast and professional space. It is also free of the very noticeable contrast and colour tone shifts you see from TN Film panels vertically.

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

On a black image there is a fairly faint characteristics IPS white glow, but in normal working conditions this shouldn't present much problem at all and is hard to spot. The above image was taken in a darkened room to demonstrate the white wide angle glow but you will notice it is far less obvious than some other models, including the 23" U2312HM. 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. Given the smaller size of this screen you should not spot any of this glow during normal operation as you glance towards the edges of the screen which was good.

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 U2212HM was very good. There was very minimal variation across the whole screen as compared with a central measurement of 120 cd/m². The luminance ranged from a maximum of 121 cd/m² in the bottom left hand corner, and down to 103 cd/m² in the top right hand corner. Two thirds of the screen was within only 5% deviance of the target and 91% was within 10% deviance. This was a positive result and showed a good performance. Results may of course vary from one screen to another but the sample we had was provided randomly from an actual retail stock so was a promising indication perhaps. We had seen a similar good performance from the U2312HM when we tested that as well.

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 very little leakage from the backlight unit here which was pleasing. There was some slight variance from the top right hand corner which you could spot with the naked eye in these conditions. This was not too severe at all and not something you'd notice in practice. There was thankfully no bleed along the edges which can prove a problem in practice. A good result again from this relatively low cost display.

General and Office Applications

The U2212HM has a nice high resolution of 1920 x 1080 which is good for side by side office work. I don't think it's as practical as a 16:10 format screen with 1920 x 1200 resolution though as you do lose a bit vertically. The aspect ratio of this screen is a pretty common trend in today's market with the move to multimedia orientated displays and widescreen formats and it was good at least to see a high 1080 resolution on a smaller 21.5" screen like this. With a pixel pitch of 0.2475mm, the text was pretty comfortable and of a decent size for prolonged office use. It was a little smaller than 23" and 24" models of course with the same resolution but didn't feel too small. Picture quality was very good using the DVI and D-sub connections, with DVI providing a slightly sharper image.

You will want to turn down the default brightness setting for the screen as the luminance is too high out of the box. A reduction from 75% to around 35 - 40% should return a more comfortable luminance around the 120 cd/m² mark out of the box. The screen is able to offer a low luminance down to 54.9 cd/m² at minimum brightness which should allow a comfortable setting even in low light conditions. The U2312HM had struggled a little more here, not being able to reach as low (114.2 cd/m² minimum).

There is a preset mode available for 'text' which some users may want to use, and it can be set up with different brightness levels independent of your other preset modes which was good. Some models are starting to use ambient light sensors and dynamic brightness control which I think can be useful for office use. It's not featured on this model however.

Ergonomically the screen was very good, with a decent and smooth range of tilt, height and pivot adjustments available. There's a rotate function as well in case you want to work in portrait mode which is arguably more useable on a 21.5" sized model like this than it is on larger screens. The easy access 2x USB 2.0 ports on the left hand side are useful for connecting printers, cameras etc, but it might have been nice to have a card reader as well like on some of the other models like the 24" U2410.

 
Above: photo of text at 1920 x 1080 (top) and 1600 x 900 (bottom)

The screen is designed to run at its native resolution of 1920 x 1080 and at a 60Hz recommended refresh rate. However, if you want you are able to run the screen outside of this resolution. We tested the screen at the next lowest resolution of the same aspect ratio which was 1600 x 900 to see how the screen handles the interpolation of the resolution. At native resolution the text was sharp as you can see from the top photograph. When you switch to a lower resolution the text is a little more blurry, but not quite as severe as some other screens we have tested. There is some minimal overlapping of the text across sub-pixels as you can see in the photo which results in this blurring. Native resolution is recommended where possible.

Responsiveness and Gaming

The screen was tested again using the chase 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:

21.5" 8ms G2G LG.Display e-IPS (W-LED)

21.5" 8ms G2G LG.Display e-IPS (CCFL)

21.5" 8ms G2G LG.Display e-IPS - overdrive ON (CCFL)

21.5" 8ms G2G LG.Display e-IPS - Video OverDrive = On (W-LED)

Like the 23" and 24" models, the U2212HM is rated by Dell as having an 8ms G2G response time which implies the use of overdrive / response time compensation (RTC) technology, used to boost pixel transitions across grey to grey changes. Unlike the larger versions however you cannot turn this overdrive control off via the factory menu and so we must rely on Dell's factory set up and control of the RTC impulse. The panel being used is an LG.Display LM215WF3-SLC1 which they rate as a 14ms G2G module. Dell have added an additional overdrive circuit to the panel to improve pixel response times. Have a read about response time in our specs section if any of this is new to you.

The performance was a very similar story to the U2312HM and U2412M really. There was a very low level of motion blur from the moving object, and no noticeable ghosting. The image remained sharp and pretty clear and was a pleasing result. The overdrive impulse was helping to improve the pixel responsiveness certainly compared with a modern IPS panel without this technology. We will show you some comparisons in a moment against a non-overdriven IPS screen. However, the RTC impulse was perhaps a little too aggressive and not controlled 100% accurately. As a result, a slight dark overshoot was introduced behind the moving car which you can see from the photos above. This was detectable in practice if you looked very closely but it was certainly not overly obtrusive.

I have provided a comparison of the U2212HM first of all above against three other 21.5" screens we have tested which use IPS panel technology and a mixture of CCFL and W-LED backlighting.  The older U2212H model showed a slightly more noticeable blur, but was free from the dark overshoot artefact. The Dell ST2220T and HP ZR2240w had also performed well in this test, being a little faster than the U2211H (older model) and again being free of the overshoot. Overall performance of those two models is quite comparable to the U2212HM.
 

21.5" 8ms G2G LG.Display e-IPS (W-LED)

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

23" 5ms G2G LG.Display e-IPS (W-LED)

23" 14ms LG.Display e-IPS (W-LED)

23" 5ms G2G LG.Display e-IPS (W-LED) - Trace Free setting 40

Above I have provided a comparison of the U2212HM against some other screens we have tested which use IPS panel technology and W-LED backlighting, this time the other models are 23" in size. The U2212HM shows less motion blur in moving images than the LG IPS231P despite that screens rather bold spec of 5ms G2G. In fact we had already concluded from our review that the IPS231P performed much like the NEC EA232WMi which has a 14ms response time and does not use RTC technology. This goes to show that you can't always trust a reported spec. The U2212HM shows a similar low level of motion blur to its larger 23" brother, the U2312HM and was also quite similar to the 5ms G2G rated Asus ML239H. However, like the U2312HM the U2212HM does have a more noticeable overshoot and dark trail unfortunately.

21.5" 8ms G2G LG.Display e-IPS (W-LED)

24" 8ms G2G LG.Display e-IPS (W-LED)

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

I have provided a comparison of the U2212HM against some other models in Dell's monitor range. The U2212HM performs very comparably to the 24" U2412M overall. In fact all three of the new Dell UltraSharp screens (21.5, 23 and 24" versions) are practically identical in these tests. They all show a low level of motion blur and a small dark overshoot when the overdrive function is turned on.

These new models are also quite similar to the older U2311H model which was a well regarded fast IPS monitor. On that screen there was no noticeable dark overshoot, but instead a slight light halo behind the moving image. Since the pale overshoot is a little less noticeable than the dark overshoot, the U2311H has perhaps the slight edge in responsiveness as a result here I think.

21.5" 8ms G2G LG.Display e-IPS (W-LED)

24" 8ms G2G AU Optronics AMVA (W-LED)

23" 8ms G2G Samsung cPVA (Response Time setting = Fastest)

24" 5ms G2G LG.Display e-IPS

I have also provided a comparison of the U2212HM against some other competing 23" - 24" models here outside of Dell's own range. The U2212HM offers the least motion blur out of these 4 models shown, and certainly a marked improvement over the fairly slow cPVA based Samsung F2380, and frankly quite disappointing AMVA based BenQ EW2420. The IPS HP ZR24W is a reasonable performer with only minimal motion blur and no overshoot. It is not quite as responsive as the U2212HM however.

21.5" 8ms G2G LG.Display e-IPS (W-LED)

23.6" 2ms G2G CMO TN Film (120Hz)

22" 3ms G2G Samsung TN Film + 120Hz

I've also included a comparison above against two gamer-orientated screens, both featuring heavily overdriven TN Film panels, and 120Hz technology. The pixel responsiveness of both of these is ahead of the U2212HM, and the 120Hz frequency allows for improved 120fps frame rates and the support of 3D content as well. The BenQ XL2410T does show some even more obvious RTC overshoot in the form of very dark trails behind the moving image (speech bubble and head) which is unfortunate, and a sign that the RTC impulse is too aggressive. The Samsung 2233RZ remains our champion in this test.

The responsiveness of the U2212HM should be perfectly fine for most moderate to high gaming and shows a nice low level of motion blur. The small overshoot is a shame really as the dark trail is an unwanted result of the applied RTC impulse. Having said that, it isn't as bad as some other models we have seen including Dell's own U2711 and certainly the gamer orientated BenQ XL2410T. There's not much in it when comparing the pixel responsiveness of the U2212HM and older U2211H but the new model perhaps has the slight edge I think as there is slightly less motion blur in practice. A good option I think for a 21.5" IPS gaming screen here.

Additional Gaming Features

Aspect Ratio Control - The U2212HM supports aspect ratio control options through the OSD 'display settings' menu as shown above. There are options for wide 16:9, 4:3 and 5:4 aspect here. A defined 1:1 pixel mapping mode is lacking here and there is also no "aspect" setting which would just retain the aspect ratio of the source input intelligently.

Preset Modes - There is a 'game' preset mode available in the menu if you want it. We have tested the screen and found the colour temperature remains similar to the 'standard' mode at ~6452k. The dynamic contrast ratio is available in the game preset whereas is it not in the standard mode, although we have already seen that this does nothing in real use unfortunately.

Input Lag

We've had some reader enquiries recently about input lag and so thought we would give a bit more information here before we discuss the results obtained for this display:

What is Input Lag?

Input lag is described as the lag between the output from a graphics card and the image which is displayed on the screen you are using. This should not be confused with pixel response time which describes the speed at which a pixel can change from one orientation to another. Pixel response times impact aspects such as motion blur and ghosting, whereas input lag is a delay between what is sent to the monitor, and what you actually see. Of course both do contribute to the overall performance and experience of the display when used for gaming.

Input Lag Measurement Techniques - The Stopwatch Program

Traditionally input lag has been widely measured by hooking up a CRT screen to the same graphics card and PC as the TFT display. By cloning the output, the user could provide a comparative test of the output of the CRT vs. the output of a TFT. A CRT would show no lag on top of the output from the graphics card which is vital for those wanting to play fast games, where reaction times are key. This is what many users are used to, having come from older CRT displays. Many high end gamers still use CRT's as well for high refresh rates and frame rates and so the move to a TFT can be worrying, especially when you start throwing in a conversation about lag of the output image.

By running the screens side by side in this way in clone mode, you can often see that the TFT lags behind the CRT. This is sometimes noticeable in practice even, but stopwatch programs have been used for many years to give a way to record and synchronise the output so that the difference could be recorded. High shutter speed photographs can then be taken to show just how much the TFT lags compared with the CRT. The level of lag really depends on the TFT display, and is controlled by many signal processing factors including, but not limited to the internal electronics and scaling chips. Some manufacturers even take measures to help reduce this, providing modes which bypass scaler chips and options which reduce the input lag. These are often reserved for gamer-orientated screens but the results are often quite noticeable.

This stopwatch method has been used for many years by many review websites and end users. It's easy to set up, doesn't cost anything and allows a reasonable comparative view of a CRT output vs. a TFT output. It can also be useful for providing a comparison between different models over time.

The method is admittedly not 100% accurate however. There are areas of inaccuracy inherent to this method. Some stopwatch programs are based on flash which can introduce issues with frame rate support, especially when viewed from an internet source and browser. The programs can introduce a degree of error if vsync is active and due to 2D native refresh rate settings of 60Hz. There's never been a defined standard for measuring input lag and so this has been used for a long time and widely accepted as a decent enough representation of what a user may experience.

 

More Advanced Measurement Techniques

Some websites take this whole area one step further and even use an oscilloscope and photosensor to measure the input lag of a display. This is of course an even more precise measurement and can help you show the true image lag along with the typical response times of a pixel transition. This is then used to give you both the overall experienced 'lag' of the image and the lag specifically between the electronics and the pixel change instruction (the pure signal processing time). We do not have access to such a method at this time and of course it would not come cheap.

We are investigating alternative means to measure input lag in the future for our reviews in an effort to help provide even more accurate results. We did not want to completely remove this section since I know it is useful to many readers and it would be missed. While it might have varying degrees of accuracy, I will say that this method has been used for many years by many sources and although there is likely a varying degree of error introduced in this method, it can still allow you to give a reasonable comparison between displays. Classification of the lag into low, medium and high for instance is possible and the method can help give you an idea of the relative output of a TFT compared with a CRT. It's an indication though as opposed to a precise measurement.

If you are particularly bothered about input lag then I would encourage you to compare results between sources and refer to other review sites as well where methods like this are used. In many cases the figures are actually quite comparable but by all means if you need absolute measurements refer to other sources as well to help with your decision.

Input Lag Classification

To help in this section we will also introduce a broader classification system for these results to help account for some of the remaining error in the method and classify 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.

On to our tests then in their current form. The Dell U2212HM showed 23.8ms of input lag on average in these tests, ranging up to 30ms maximum. This was a moderate level of lag and quite similar to some of the other screens we have tested like the HP ZR2240w (25ms). It was only slightly longer than the lag of the 21.5" Dell ST2220T (16.3ms) and U2211H (15.6ms) to be fair, but was a little slower in our tests. The screen is therefore within the Class 2 category of input lag.

Movies and Video

 The following summarises the screens performance in video applications:

• 21.5" screen size makes it a quite small option for an all-in-one multimedia screen, and quite a bit smaller than modern LCD TV's of course. A larger 23 - 24" would be more suited certainly.

• 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.

• 1920 x 1080 resolution can support true 1080 HD resolution content

• Digital interface DVI supports HDCP for any encrypted and protected content

• Additional DisplayPort interface is available although it would have been useful to feature HDMI as well here as it is popular and very useful for external Blu-ray / DVD player connectivity.

• Black depth and contrast ratio are excellent for an IPS panel. Detail in darker scenes and shadow detail should not be lost due to these measurements.

• Dynamic contrast ratio is available but does nothing in practice unfortunately.

• 'Movie'' preset mode is available from the preset menu. This made the image a lot cooler than the standard mode which is probably not very useable I don't think. It also provided access to the DCR mode which as we've said, does nothing anyway.

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

• Wide viewing angles thanks to e-IPS panel technology meaning several people could view the screen at once comfortable and from a whole host of different angles.

• Very good ergonomic adjustments available from the stand allowing you to obtain a comfortable position for movie viewing.

• No significant backlight leakage from the panel which was pleasing. Thankfully no leakage along any of the edges which has the potential to become distracting when watching movies, especially where black borders are present.

• No integrated stereo speakers on this model but it is compatible with Dell's sound bar for some light sounds for movies if needed.

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

Dell U2211H Comparison

I know many people are going to be asking the question: "which is better, the U2211H or U2212HM?" Unlike with the 24" model, the U2212HM is a direct replacement of the U2211H, being part of their almost annual refresh and moving the range away from CCFL backlighting and to W-LED instead. I will provide a comparison here between the new and old model to help you understand what has changed both from a technical and from a performance point of view.

Dell U2211H vs. U2212HM Comparison

Backlighting

As with the U2312HM update, the major change since the U2211H model has been Dell's move towards W-LED backlighting from CCFL. Both screens offer a standard gamut colour space, but W-LED is certainly the popular choice of manufacturers at the moment. This has environmental and energy saving implications which are of course attractive given the focus on carbon footprints and the like. The LED panels are arsenic and mercury-free for example. We measured the U2211H as having a 23.3W power consumption after calibration (to 120 cd/m²) and we have measured the U2212HM as being ever so slightly lower once calibrated at 21.9W.

It should be noted that W-LED backlighting does not necessarily offer you any advantages in terms of colour reproduction, contrast ratios, black depth, or uniformity. These are often incorrectly assumed to be impacted by the change, when in fact those are features of the panel itself rather than the backlighting unit employed. The use of W-LED does allow for a thinner profile of the screen with the U2212HM measuring 59.5mm depth, while the U2211H was 65.0mm.

Features and Specs

The U2211H and U2212HM are pretty much identical here, and the only thing that has really changed is the design. The U2212HM has more rounded edges to the bezel and stand compared with the rather square appearance of the U2211H. This was the same story for the 23" models.

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) 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:

• Features - Both the same

• Interfaces - Both the same

• Calibrated power consumption - the calibrated consumption of the U2212HM is a little lower thanks to its W-LED backlighting.

• Panel Uniformity - The U2212HM wins here with a much better luminance uniformity than the U2211H from our tests

• Office and Windows - Nothing to really separate them here

• Viewing angles - again, nothing to really separate them

• Movies Overall - I've given the slight edge to the U2211HM because of its better calibrated black depth and contrast ratio, which will help with shadow detail and darker scenes. It also has a better luminance uniformity.

• Responsiveness - They are all very close really but I've given the very slight edge to the U2211HM since it offers slightly less motion blur. Even though there is a small dark overshoot introduced, the U2212HM is a little faster and more suited to gaming I think. Very close call to be fair.

• Input lag - both are pretty low really but the U2212H has the advantage with 15.6ms average lag, compared with 23.8ms of the U2211HM.

• Minimum luminance - The U2211H can reach a lower luminance than the U2212HM at 23 compared with 54.9. This might be more suitable for those working in darker lighting conditions or who are sensitive to brightness of screens although both screens should be fine given their backlight adjustment range.

• Colour accuracy Default - Out of the box the U2212HM had the very slight edge at dE average 2.2 compared with 2.3 of the U2211H. It also had a more accurately set up white point and gamma curve.

• Colour accuracy calibrated - nothing really to separate the two once calibrated.

• Calibrated Black depth - Both models were impressive for IPS based screens but the new U2212HM has the edge at 0.12, as compared with 0.14 of its predecessor.

• Calibrated Static Contrast Ratio - again thanks to its lower black depth the new U2212HM has a 1013:1 static contrast ratio after calibration, better than the the U2211H at 864:1

• Dynamic Contrast Ratio (DCR) - Neither really work at all, but the higher static CR of the U2211HM means that DCR is 1026:1, whereas the U2112H's DCR is only 983:1. Not really anything in it in practice as neither work properly.

Overall there is not a huge difference between the new and the old model. Both ultimately offer the same features and specs with the only significant change being the move from CCFL to W-LED backlighting. To the end user this doesn't really signify a massive difference in real terms. The profile is a bit thinner and the power consumption should be a bit lower, but it doesn't really wow you or even matter in day to day situations. From a performance point of view there seemed to be a much better uniformity to the new model. Let's hope that extends to other samples and units as well as this could present a positive change which would impact the end user. There was nothing really to separate the two when it comes to colour accuracy and out of the box performance and the gaming responsiveness and input lag were also very similar at the end of the day. The new model offers a slightly improved contrast ratio and black depth which is good.

Taking everything into consideration the U2212HM does just seem to be a pretty even replacement for the U2211H. It has allowed Dell to move towards LED backlighting, and no doubt attract a new "generation" of buyers, but to be honest the overall performance and characteristics make them very similar. Not enough has changed to allow us to really say that the U2212HM has made a big improvement unless patterns with uniformity continue, which would be a welcome improvement from the new model.

Conclusion

The U2212HM was another welcome addition to Dell's very popular UltraSharp range. It hadn't made a huge amount of changes or compared with its predecessor, the U2211H, but the move to W-LED backlighting is popular right now. There were a few performance improvements worth mention as well including a higher contrast ratio and better panel uniformity. The features and specs were as we have come to expect from a Dell screen really and it was good to see they had not made any cut-backs with the updated 2012 model. A great range of easy to use ergonomic adjustments from the stand, and a decent enough range of connections and features.

Performance wise the default set up was good, and should be fine for most casual users without the need for calibration equipment. Black depth and contrast ratio were excellent as I have already said, and thankfully the luminance control range from the OSD menu was good. This was something which had been a potential problem with its larger 23" brother when we tested it. Pixel response times were basically the same as we'd seen from the 23" and 24" equivalents, with a low level of motion blur and a good performance which should be fine for most gamers wanting an IPS panel. The use of IPS of course gave us a great all round performance in other areas such as viewing angles and office use. As is becoming far too common, the dynamic contrast ratio was useless in practice which was a shame. Of other note was the poorly set up colour temp modes from the OSD menu, which all seemed to be too cold apart from the 6500k mode which admittedly is probably the most used and important.

The screen is available at a very low cost of �173 GBP (inc VAT). This does make it a little more expensive than some TN Film based models in this sector of course, but for an IPS panel with very good all round performance it is a good price. It's about �23 cheaper than the 23" version so can save you a bit of money if you don't need a slightly larger model. Well worth a look I think.
 

Further reading: TestFreaks
Some images courtesy of Dell.com