Original Link: http://www.anandtech.com/show/7336/nec-pa242w-monitor-review



Updated 10/2/2013: Review has been updated to correct an issue with the non-SpectraView data. Please review the sRGB and AdobeRGB pages again if you have read this article before as they have been updated. The conclusions have been updated to match these test results as well.

What separates a professional grade monitor, like the NEC PA242W, from a similarly designed consumer display? You can easily go to Dell and find a 24”, 1920x1200 resolution display with GB-LED backlighting for a few hundred dollars; why are displays like the NEC PA242W worth almost twice the price? Are they just coasting off the reputation they had from their CRT days, or do they engineer their LCD displays in a way that set them apart from everyone else? I set out to examine the PA242W and find what it offers that sets it apart from the competition.

The NEC PA242W is a 24”, GB-LED backlit display with 1920x1200 resolution. I recently saw GB-LED backlighting in the Dell U3014 monitor and it performed well. GB-LED backlighting allows for the full AdobeRGB color gamut while still using LED lighting. Also on the NEC are a full complement of inputs: HDMI, DisplayPort, DVI, and VGA, as well as a 3-port USB hub. I would like to see USB 3.0 on the hub for the price of the NEC but we only get USB 2.0. What you do get are dual USB upstream ports, letting you connect the NEC to two computers. Video inputs can be assigned to a USB upstream connection, so when you switch the display from one PC to another, your connected peripherals switch to that PC as well.

You realize the NEC PA242W is different as soon as you open the box. There is no attaching a stand with screws or clicking it in. The whole monitor is fully assembled, ready to be lifted out of the box and put to use. The construction is unlike other displays: solid and thick, with a handle at the top to lift it out. The stand is a nice ergonomic model that allows for a wide range of adjustments and is already set up. The bottom of the display houses all of the inputs and USB outputs.

As soon as you use the OSD you’ll realize the NEC PA242W is unlike conventional monitors as well. Brightness is measured in cd/m^2 instead of a random slider. It is fully adjustable in 1 cd/m^2 increments up to 240 cd/m^2. You can adjust it beyond this but the control turns red indicating that the display uniformity will suffer. There are five monitor presets that you can control with a variety of settings: Colorspace, Brightness, Contrast, Gamma curve, White Point, and more. Moving between sRGB and AdobeRGB can be done at the touch of a button.

The selections for white point and color space go well beyond the usual options. White Point can be set from 3000K up to 15000K in 100K increments. Colorspace offers AdobeRGB, DCI, sRGB, Native (Full), SMPTE, and more. Any photo or video editing you need to do with the NEC PA242W should be covered by these options. The menu system is also very easy to use, with Up/Down and Left/Right arrows, on-screen labels, and a simple design.

All of these options provide supreme control over the NEC PA242W. There's even a standard 4-year warranty with 48-hour replacement. The real question is if the on-screen performance matches up with the controls.

NEC PA242W
Video Inputs DVI-DL, DisplayPort, HDMI, Dsub
Panel Type AH-IPS
Pixel Pitch 0.27mm
Colors 1.07 Billion
Brightness 340 mc/m^2
Contrast Ratio 1000:1
Response Time 8ms
Viewable Size 24.1"
Resolution 1920x1200
Viewing Angle (H/V) 178/178
Backlight GB-R LED (20 kHz PWM)
Power Consumption (operation) 56W
Power Consumption (standby) 0.2W
Screen Treatment Anti-Glare
Height-Adjustable Yes (6")
Tilt Yes
Pivot Yes
Swivel Yes
VESA Wall Mounting Yes, 100mm x 100mm
Dimensions w/ Base (WxHxD) 21.9" x 14.9" x 9"
Weight 23.4 lbs.
Additional Features USB hubs with KVM switch, 3D LUT,
Limited Warranty 4 years with 48-hour replacement
Accessories Power Cord, DP Cable, MiniDP Cable, DVI-D Cable, USB Cable
Price $1,049

 



As noted on the previous page, NEC limits the upper level of the PA242W backlight to 240 cd/m2. You can go beyond this, but the control turns red to let you know that overall performance is suffering. The construction of the PA242W is designed to make it as uniform and even a display as possible. Pushing the backlight too far will reduce that. No one that is using this monitor in a professional setting would need light output beyond that, so I used that level for the maximum setting here.

If you want to go beyond that, the NEC can produce 287 cd/m^2 at maximum. The minimum setting produces 41.19 cd/m^2, very close to the on screen reading of 40 cd/m^2. The 240 cd/m^2 setting produces 236.7 cd/m^2, also very close. You can adjust this to any level between in 1 cd/m^2 increments. For white level control, the NEC PA242W is unmatched in my experience.

White Level -  XR Pro, Xrite i1D2 and XR i1DPro

Black level is not quite as good as white level. At the 240 cd/m^2 level we have a black level of 0.4001 cd/m^2 and at the minimum setting we see a level of 0.0799 cd/m^2. That is a very low minimum, but no other monitor has a minimum setting of only 40 cd/m^2 either.

Black Level - XR Pro, Xrite i1D2 and XR i1DPro

The contrast ratios that result from the above are only fair, 515:1 for the minimum setting and 592:1 for the 240 cd/m^2 level. Curiously the maximum setting produces a contrast ratio of 699:1 indicating that the NEC can do better if you sacrifice uniformity. For movies and TV people typically value contrast ratio above all, but for production work, uniformity might be more important. We will see if this sacrifice winds up being worth it later.

Contrast Ratio -  XR Pro, Xrite i1D2 and XR i1DPro



Updated 10/2/2013: Talking to NEC after this went live it was found that the review unit had a feature, Metamerism, enabled. This helps to match it to other displays, but also caused the pre-calibration numbers and non-SpectraView numbers, to be incorrect. I'm currently re-running the pre-calibration numbers on the NEC now and updating the pages as fast as possible. The end result is that the NEC performs far, far better out-of-the-box than initially thought.

Be prepared, as there is a lot of bench test data coming here. For my pre-calibration settings I used the sRGB color gamut, a color temperature of 6500K, and a gamma setting of 2.2.

 

Pre-Calibration

(re-tested)

Post-Calibration,
200 cd/m^2
Post-Calibration,
80 cd/m^2
White Level (cd/m^2) 197.0 204.14 80.79
Black Level (cd/m^2) 0.3457 0.366 0.1479
Contrast Ratio 570:1 558:1 546:1
Gamma (Average) 2.2633 2.1437 2.3734
Color Temperature 6460K 6426K 6442K
Grayscale dE2000 1.573 0.6504 0.6473
Color Checker dE2000 1.0198 0.6392 0.5331
Saturations dE2000 0.9682 0.6722 0.5675

Out of the box the NEC is practically perfect. The grayscale has a little bit of an error but one that should barely be visible if at all. The gamma has a small peak at 95% but no huge issues at all. The colors are reference quality and there is nothing to complain about with them. If this was a post-calibration result I would say it is amazing. The fact that it is a pre-calibration one makes it even that much more incredible.

Post calibration, aside from a dip in the gamma at 90-95%, everything else improves and becomes practically perfect. Yes, the overall error levels can be lower but you couldn't see it. None of the 96 samples in the large color checker chart even come close to a dE2000 of 2, much less the visible limit of 3. The average error of 0.63 is the lowest I've ever seen. It's perfect.

When targeting 80 cd/m^2 and the sRGB gamma target we see similar performance. The gamma curve isn’t perfect but really everything else is. The color checker chart hits an average dE2000 of 0.53 here which is even better, but not visible. What you see on the screen is what you are supposed to see.

With Metamerism turned off, the NEC measures perfectly. The only improvement I could see is in contrast ratio, but they might be letting that suffer to coax more reliable overall performance of the panel which is a trade-off that would be worth it for their target markets. Perhaps once OLED gets affordable we can see something better, but until then this is really, really good.



For the AdobeRGB testing the targets are the same as sRGB except for colorspace. Light output, gamma, and everything else remains the same.

 

Pre-Calibration

(updated)

Post-Calibration,
200 cd/m^2
Post-Calibration,
80 cd/m^2
White Level (cd/m^2) 199.7 200.2 79.55
Black Level (cd/m^2) 0.3328 0.3645 0.1501
Contrast Ratio 600:1 549:1 530:1
Gamma (Average) 2.2265 2.18 2.4294
Color Temperature 6442K 6507K 6472K
Grayscale dE2000 1.2235 0.5104 0.8575
Color Checker dE2000 0.8203 0.7093 0.7103
Saturations dE2000 0.8436 0.7073 0.6561

AdobeRGB performance is similar to sRGB performance before calibration. The grayscale has tiny, tiny errors but that's it. The gamma is even better than before, and so is the color gamut. This is all right out of the box, using the AdobeRGB preset. Even the on-screen brightness number is only off by 1 cd/m^2 or less. That might even be instrument positioning error that accounts for that. I really fail to even see the point of calibrating a display like this. It comes out of the box so perfect, that I can't imagine wanting it much better.

Post-calibration with a 200 cd/m^2 target the AdobeRGB calibration is slightly better than with sRGB. The gamma is more accurate and the grayscale errors are slightly smaller. Color errors are non-existant and nothing else is here to complain about. Basically the NEC is perfect here.

With the 80 cd/m^2 target it is virtually identical as well. The gamma is better than in sRGB mode and everything else is so close as to not matter. Invisible error levels are still invisible. There's nothing to complain about here at all.



NEC offers their own calibration software, SpectraView, for their monitors. Most software packages like CalMAN work with the video card LUTs to improve calibration, and the monitor LUTs if they can access them. The NEC PA242W contains a 14-bit, 3D LUT that allows you to correct the output to be almost perfect. Using SpectraView, NEC will reset your video-card LUT to be neutral and rely only on the monitor LUT so it will work correctly afterwards on almost any PC.

You can use a wide variety of meters with SpectraView but I chose to use my i1Pro. It isn’t as good at low-light as the C6, but it's more color accurate. The C6 is accurate if you profile it, but the NEC software does not allow for this. Once connected you choose your targets (D65 white point, 2.2 gamma, 200 cd/m^2, and sRGB gamut here) and then the software calibrates the PA242W. The calibration is also much quicker than CalMAN, which is nice. You can save multiple different targets in the SpectraView software and then load them back up later if you need to work in multiple environments.

After the calibration I measured again with CalMAN using the same settings as before to see if this works better than CalMAN on its own. To see how this performs I had CalMAN measure far more points than usual, which takes a long time.

  CalMAN Calibrated,
200 cd/m^2
SpectraView,
200 cd/m^2
White Level (cd/m^2) 204.14 200.6
Black Level (cd/m^2) 0.366 0.3827
Contrast Ratio 558:1 524:1
Gamma (Average) 2.1437 2.1596
Color Temperature 6426K 6458K
Grayscale dE2000 0.6504 0.706
Color Checker dE2000 0.6392 0.8781
Saturations dE2000 0.6722 0.7461

The NEC software produces very similar results. The contrast level is a little worse, but the light output level is slightly more accurate. Everything else is close enough as to be a draw where this is concerned.

Average saturation and color checker dE2000 errors are below 0.9, which is incredibly impressive. No individual measurements rise over a dE2000 of 2.0, and that means you should have no visible errors now. None. 

When I re-ran the NEC Calibration and targeted 80 cd/m^2 instead of 200, the results are not nearly as good. This might be due to using the i1Pro and it not performing as well in lower-light situations. It also might just be that the method the software uses is not as effective at lower light targets. With these I find the CalMAN calibration to perform better.

The SpectraView software also allows you to save your calibrations and recall them. You can select your saved settings from a drop-down list and it will reload the LUT into the monitor. If you're regularly moving from sRGB to AdobeRGB or other colorspaces and back, this makes it easy to do so. It also avoids using the video card to make it more reliable than other methods.

After using the SpectraView software and seeing what it can do, I’d suggest it should be considered possibly essential for this display. The ability to save and recall multiple presets makes working with the monitor with different media, or lighting conditions, simple and easy. There is no worrying about the display not being setup ideally for whatever environment you need to work in. Also worth noting is that by going directly to the monitor LUTs, the final calibrated colors will be used regardless of what program you run; this isn't always the case with video card LUTs, as games and videos will sometimes bypass those, and it's one more feature that sets a display like the PA242W apart from consumer models.



With the switch to CalMAN we have been able to use much better methods for measuring display uniformity. Instead of getting unique dE2000 values for each point on the screen, they are compared to the center of the screen to give us a true uniformity value. We also measure 24 patches so we have a much more accurate idea of overall color and brightness uniformity than just measuring white level. Now with the test data from the NEC PA242W, I can finally use it to show why a professional monitor costs so much more.

Look at the white uniformity data. I usually am very happy if nothing varies from the center by more than 10%. On the NEC PA242W the maximum variation is 4.2%. A white field on the screen is white, and it is the same level everywhere. No monitor before has come close to this performance, which is a testament to the design of the NEC backlight setup.

Black uniformity is not nearly as good as white. Two corners are much darker and two are much lighter than the center. I’m surprised by this as good uniformity usually works both ways, but it seems that white uniformity is being judged to be more important overall than black uniformity here.

Since the white uniformity was almost perfect, this is just a mirror of the black uniformity chart. Two corners have much higher contrast ratios and two are much worse. It’s a bit disappointing just like the black uniformity is.

The color error uniformity is not disappointing at all. Instead, it is practically perfect. No area of the screen has an average dE2000 error >1 compared to the center. Since an error less than 1 is invisible to the eye, even on still images, this really is perfect. Even if the numbers were lower you wouldn’t see a difference, so I will just say this is perfect.

Uniformity like this has not been seen in my testing before. This performance is what professional designers and photo editors’ need, and it is what NEC delivers. It is expensive, but for many people it is worth paying for as it has untouched uniformity performance.



Input Lag is tested on the NEC PA242W using the HDMI input and the Leo Bodnar lag tester. This uses a 1080p signal so there will be some scaling involved, but the 3D LUT is far more likely to cause a decrease in performance. The lag on the NEC PA242W measures just over 27ms. This is more than many gamers would want to put up with, but the NEC PA242W isn’t really targeting gamers either. That lag is low enough that professionals that want it and also want to game sometimes should be fine, but hard-core gamers will be looking elsewhere.

Processing Lag Comparison (By FPS)

Despite its smaller size and use of LED backlighting, the NEC uses a good bit of power. With its minimum light output of 40 cd/m^2 it consumers 24 watts on an all-white screen. At the maximum normal setting of 240 cd/m^2 it consumers 49 watts. Both numbers are relatively high for the size, and result in low efficiency numbers.

Candelas per Watt

LCD Power Draw (Kill-A-Watt)

With a G-B LED backlighting system, the NEC PA242W has a gamut larger than the AdobeRGB standard. Because of its internal LUT and correction modes, you are free to choose the appropriate gamut for your work and not have constantly over-saturated colors. For users that need the larger gamut support, NEC delivers it but not at the expense of sRGB and other standard.

LCD Color Quality



When I revamped the monitor testing system, displays like the NEC PA242W were the reason why. The fact is that almost any monitor that is reasonably well designed can perform well after a calibration the way most people review. If you really want to know what separates a display like the NEC PA242W from standard consumer displays you need to push it harder. That means testing things like 25-point uniformity, multiple colorspaces, and as many data points as possible.

Thankfully NEC has delivered a monitor that shows off what can be done and has amazing performance on our test bench. Straight out of the box the performance is practically perfect. Even the pickiest user is going to find the NEC image to be as good as it can get without any tinkering. Using the SpectraView software you can take this down even more and make it easy to switch between as many calibrated presets as you would like. The only area that could use some improvement is the absolute black level. Otherwise the NEC PA242W leaves me with nothing to complain about when it comes to image performance. It really is the closest thing to perfect that I have seen.

This performance comes at quite a cost. $1,000+ for a 24”, 1920x1200 monitor is a lot of money to spend today. Of course factor in that you are saving the money from not needing calibration hardware or software and that price becomes more reasonable. So the real question is: do you need this? If you’re asking that question then you probably don’t. If you saw perfect color, perfect uniformity, and knew that you needed it, then you’re probably more willing to pay the price as it is essential to your work. No monitor that I have seen can be pulled out of the box and, provided you check the options more carefully than I initially did, provide a better image with no extra work.

Displays like the NEC PA242W are expensive, but they also push the boundaries for what a display can do. Technologies like 3D LUTs and more uniform lighting will likely trickle down to more affordable hardware, but it will take time. For now if you want the most accurate, most uniform display that you can buy, you want the NEC PA242W. It’s designed with image/video professionals in mind, and it performs admirably.

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