NEC PA241W Review
The PA241W is a promising addition to the category of high end, professional-grade LCD monitors. It has all the features a color professional or photographer would want: A wide, AdobeRGB-like gamut, excellent uniformity, the SpectraView II profiling software creates a quality calibration and profile, and a surprise to me was to see what good, dark blacks it can produce. In fact, I'm hard pressed to find anything wrong with it, but I'll share my thoughts as we go along. This review assumes the user would be using either of the NEC programs for calibrating this display since they are the only available means of accessing the internal graphics.*
Almost all of the new monitors in this class that have been coming out in the past year are featuring a wide color gamut as a standard feature, and the PA241W is no exception. This gamut is right in line with what we have been seeing for wide-gamut monitors. It closely resembles the color space of the Eizo CG243W. The NEC literature claims 98.1% coverage of the AdobeRGB gamut and my estimate would confirm that. It does not encompass the entire AdobeRGB space, but it is very close, and close enough to be very effective for viewing these colors. The profiles I made show the PA241W producing more colors in the saturated reds and magentas, and ever-so slightly fewer yellows and yellow/greens than the AdobeRGB space. Photographers using AdobeRGB as their working space will be in good shape, and those using ProPhoto will get to see the added reds on this display.
We have created several profiles using the NEC SpectraView software and using the various measurement devices it supports:
Gamut volumes are calculated using ColorThink Pro. Since gamut volumes vary depending on the instrument used, note that it is best to use the i1Pro or the SpectraView II sensors for measurements and gamut calculation since they will be more accurate. (For example, while the i1Display2 measurement creates a profile with a larger gamut volume, this is misleading as the i1 Display2 will be less accurate than the i1Pro or the SpectraView II sensor.)
|Gamut volume with monitor profiling instruments
|NEC SpectraView II device>
|i1 Display 2 colorimeter>
Until it becomes possible to pass more than 8 bits of color data through a computer graphics card, all wide-gamut displays must have some kind of supplemental, high-bit, internal graphics ability in order to be up to the task for color professionals. All high end display manufacturers offer their own software to calibrate their internal graphics processors, and SpectraView II is the NEC software that is made specifically for calibrating NEC displays. It requires use of any modern colorimeter or spectrophotometer, and the best results are obtained through use of their self-branded NEC SpectraView II colorimeter. This combination seems to work very well, creating profiles that are virtually identical to those made using an i1Pro spectrophotometer, with the added benefit of getting even better black measurements than the i1Pro. Profiles made using other colorimeters (even an non-NEC i1 Display 2) yielded far different results, and so they should not be trusted for saturated color accuracy. We would recommend using either the NEC-branded colorimeter, or a spectrophotometer such as an i1Pro or ColorMunki.
All the options you would want are there in the SpectraView II software, including:
- Dialing in your own custom white point, gamma and luminance,
- Ability to create presets, so you can easily calibrate to the same settings every time,
- Setting a reminder to tell you when to profile the display again,
- They even offer several different ways to determine your white point: including measuring your printing paper with an instrument, adjusting the red green and blue values, x/y coordinates and Kelvin numbers. If you don't understand any of these, that's okay - the software is actually very easy to use. There are presets already installed to get you started and it's easy to create new aimpoints for your own custom setup.
SpectraView only creates matrix based profiles (not look up table based profiles), and the software cannot be used to calibrate non-NEC displays, so you will need some other profiling package to calibrate your other monitors.
Alternatively, you can use a new NEC program called MultiProfiler to calibrate and profile the display without the use of a measurement device. This works better than it might sound. Using the precise factory calibration as a baseline, the software will create a profile based on AdobeRGB, sRGB, REC 709, the full gamut of the display, or a custom setting. The custom setting can be used to emulate another display or a printer. The key part of this program is that it enters these gamuts into the Look Up Tables (LUTs) in the display's own graphics processor. This seemed to work very well in our tests. Since this function is dependent on the factory calibration for accuracy, it is uncertain how accurate MultiProfiler will be as the display ages over time.
There has been some excitement about using this feature to emulate a typical printer profile: Plug your printer profile into the custom setting, and the display will show everything that is displayed as if it were printed on the printer. With this scenario, the user would not have to do a "soft-proof" in Photoshop in order to see what the image will look like when printed. In fact, because the display itself contains the correction, there is no special program that is required to soft-proof.
When I set up MultiProfiler to emulate my printer profile, it gave a pretty good representation of what my prints look like. It is critical, of course, to adjust the screen to emulate the white point of your paper white, and the MultiProfiler wizard provides the ability to set your white point, luminosity and gamma. Once I dialed that in, it was remarkable how close the on screen image was to my prints. I did notice that the screen was a bit lacking in contrast compared to the prints. There does not appear to be a means of emulating Photoshop's Black Point Compensation in MultiProfiler, so I might attribute contrast differences to that.
Note that this turns the entire display into a "printer-proofer" - not just a single window. Those of us used to soft-proofing in Photoshop may find this a bit disconcerting. We are not used to seeing everything on the screen as interpreted by the printer profile!
Of personal interest, is an elementary 3D graphing ability in MultiProfiler. Tucked away in a corner is a check box for viewing a 3D graph of the LUT it is going to make. CHROMiX is famous for the graphing ability in its ColorThink programs, so we're always interested in how other programs present information in 3D. In this case, you can click on any of the printer profiles on your system and immediately see, in glorious 3D, the precise points in the Look Up Table that the program will be emulating. Perhaps this could be useful for comparing gamuts of different printers?
Finally, an important option in MultiProfiler is a "metamerism correction" checkbox. Many people work with more than one display connected to one computer, and it can be a challenge to get them all to match - even when using the same settings. Multiprofiler provides this "metamerism correction" which helps make it more likely that this wide gamut monitor will match a similarly-calibrated standard gamut monitor.
The uniformity across the screen was very good. The average delta E difference between various locations on the screen was around 1.07, which means that on average, the difference in color between one place on the screen and another place is only just barely visible with the human eye. The worst uniformity issue I found on my demo unit was between the upper right corner and the lower left corner which showed a dE of 3.09. That is still a variation that is hardly noticeable by most people. If that's the worst it gets, then that's still considered to be very uniform across the screen. By way of comparison, Eizo has a policy of keeping the uniformity discrepancies of their high end displays to less than 3.0 max dE, and our tests have shown that they come very close to that as well. So our test PA241W came very close to the Eizo standard.
The NEC uniformity is corrected for at the factory using a technology they call ColorComp, and Digital Uniformity Correction. While uniformity is excellent when new, this leaves open the question of how well the uniformity holds up over time. (NEC has a four-year warranty.) If you have occasion to run this display very bright, the software will warn you if it needs to reduce uniformity in order to hit the high luminance you are aiming for. (This does not happen unless you are try to run at something like 230 cd/m2.)
Numbers don't tell everything, so we make a visual check of the display using grays and whites on a full screen. Visually this display looks very uniform, except for 1/4 inch to 3/4 inch around the very edges where there is a barely visible darkening. This issue with the edges is normal for an LCD.
Much importance is place on an LCD monitor's ability to reproduce blacks and near blacks well. This is one of the main complaints about LCD displays from those who are used to a CRT. Blocking a backlight with liquid crystals is quite effective, but it's not as good as not having that light blasting away to begin with. Contrast ratios advertised with various displays are dependent on not only how bright a monitor can be, but also how dark. Different measurement devices have different capabilities in their abilities to measure black. The X-rite DTP-94 colorimeter has a noise-filter circuitry built into it which allows it to measure black more accurately. When looking at black measurement numbers, the lower the number, the darker is the measurement and the richer your blacks will be.
Using a DTP-94 on the PA241:
- At 120 cd/m2 brightness, the black point is .20
- At 60 cd/m2, the black point is .11
These black level numbers are the best I've ever seen with an LCD display! However, the DTP94 does not give the most accurate reading of extremely saturated colors, so most people will want to calibrate with the NEC SpectraView II colorimeter:
Using the NEC SpectraView II device calibrated to 272 cd/m2 (max brightness), we measured .49 cd/m2 max black.
- At 120 cd/m2 brightness, the black point is .21
- At 60 cd/m2, the black point is .13
These numbers are still very, very good for black level. By comparison, the typical off-the-shelf LCD display runs around .30.
At maximum brightness the display was able to hit 272 cd/m2. We also calibrated and ran it at down at 60 cd/m2 without seeing any problems with shadow detail, banding, etc.
Other manufacturers have a warning against running the display at high brightness levels, but there was nothing I could find in NEC literature about that. NEC does offer some warnings against leaving a motionless image on the screen for a long time (which contributes to temporary image latency).
Banding / grayscale
Even at low luminance levels (60 cd/m2), I could not detect any colored banding on a gray scale gradient. The gray looks very neutral. I could detect a very small amount of neutral banding from about 25 - 30 %.
The software will warn you if you are moving your luminance level so low that your contrast ratio will be diminished. (This typically does not happen unless you are running down to less than 50 cd/m2, which is pretty dark!)
Highlights / Shadows
I am able to easily distinguish highlights and shadows of 1 L value difference in Photoshop.
Angle of view
The specs report an viewing angle of 178o which seems to be about right. There is no problem viewing image uniformly from one side of the display to the other. If viewing extremely off-axis, we will see changes in color and brightness as is expected. Up-and-down variation is a bit more pronounced than the side-by-side variation.
Rotation and monitor stand
The display rotates on the stand between vertical and horizontal. There is no "automatic" image rotation - although the OSD rotates with the screen automatically.
The display and the stand together are quite heavy, and there is a "handle" built into the top of the back of the monitor to allow for easier lifting and moving. It is a useful feature to have because this monitor is heavy. The 271 weighs in at 30 lbs. and the 241 at 23.8 lbs.
The stand allows movement from as far down as almost sitting on the table top - to about 6.5 inches high. It can swivel left and right and has a total movement of about 90 degrees, although it might take an extra push to get it going at first. The face of the display can be positioned from about -5 degrees (more than fully upright), to laid back at about 20 degrees.
More items of secondary importance to photographers
There is a switchable, built-in USB hub which essentially allows you to control two computers with only one keyboard and mouse. Several displays out there allow you to switch between video input signals, but if you run your USB keyboard and mouse cables into and out of this built-in USB hub, you can use the switches on the front of the display to quickly switch between two computers, and continue using just one set of keyboard and mouse for both.
The PA241 is a 24-inch diagonal screen which measures out to about 20.4 inches wide by 12.75 high. This is more than enough to fit the images of two 8.5 x 11 sheets side-by-side.
There are 3 different video protocol connection types on the PA241W:
- DisplayPort (1 port),
- DVI (two ports)
- VGA 15-pin D-sub (1 port).
VGA (analog) is provided to be able to handle older legacy connections or a 2nd monitor, but it is not recommended for serious color work. A digital connection (DisplayPort or DVI) allows you to benefit from the unit's internal graphics. DVI-D has been the standard for a few years now and gives great performance at 8-bit depth for each channel out a palette of 16.7 million RGB combinations. DisplayPort on the other hand provides up to 10-bits per channel out of a palette of 1.07 billion RGB combinations. Believe it or not, we found no difference with 'color management-level' accuracy between these two viewing environments. Granted, more color 'depth' is visually evident when viewing with 10-bit resolution via DisplayPort (versus DVI), but for those users whose highest priority is color accuracy, both connection types allow comparable calibration and profiling results. More visual information doesn't equate to more sampling information for the emissive measurements.
A compatible display (such as an NEC PA-series display) and DisplayPort connections are just two of the components necessary in order to view true 10-bit color depth on your computer system. For this to work, every component in the chain requires 10-bit support. So you also need your application (ie: Photoshop), operating system, video card, and video card driver to support 10-bit color as well.
One of the last hurdles has been finding a PCI v2 DisplayPort compatible video card that works with your system and is affordable. There are several mainstream cards from ATI, nVidia and Matrox that work well, but are pretty expensive right now as this is a newer technology. Currently only the very high end cards offer 10-bit DisplayPort support even though there are many that offer DisplayPort connections.
Video drivers for Windows are available from NEC if needed: http://www.necdisplay.com/SupportCenter/Monitors/InstallDrivers/?section=displaydevice But most modern Windows operating systems will recognize the monitor as a Plug and Play device. Mac operating systems will automatically read the monitor information and list the available resolutions and refresh rates in the System Preferences/Monitors.
DDC connection with CEDP
ColorEyes Display Pro is a popular third party profiling software that can often be used to calibrate the internal processors of these high end monitors. Unfortunately NEC is not allowing the ColorEyes Display folks access to the internal LUTs, so you cannot interface with the DDC capabilities of this monitor using ColorEyes Display. Eizo, Apple, Samsung, LaCie all work with ColorEyes Display, but not NEC. However, there is a workaround for those who would like to build a CED profile on top of the SpectraView internal calibration.
Also, we have found that the NEC SpectraView II device works differently with the NEC software than it does with other programs, like CED. Therefore we recommend that you calibrate and profile using a spectrophotometer if you are using any other than NEC software.
Watch out for the suction cups
I found the brand-new NEC SpectraView II device to have very active suction cups. The SpectraView instructions takes pains to warn you not to press the suction cups against the screen surface. This is good advice since they stick very easily.
NEC does offer a hood for a 24 inch display (NEC hood part# HDPA212426) which can be purchased separately:
or, see the CHROMiX Blog for ideas on making a monitor hood:
- 1920 × 1200 native resolution
- 1000:1 contrast ratio
- 360 cd/m2 brightness
- DisplayPort, DVI-D (2) and VGA 15-pin D-sub
- Viewing Angle 89º/89º/89º/89º
- Warranty 4 years parts and labor, including backlight
- Additional Features: USB hub (2 up/3 down) with DisplaySync Pro, Picture-in-Picture, Side-by-Side, ICC Profile Emulation, Color Vision Emulation, 14-bit 3D gamma, Adobe RGB, DICOM, ColorComp, overdrive, ECO Mode, cable management, touch-enabled, tilt, swivel, pivot, 150mm height-adjustable stand with locking base, No Touch Auto Adjust, quick release stand, VESA Mount, TCO 5.0
Links and other information:
- All tests were run at 110 cd/m2, D6200 K, 2.2 gamma; NEC-i1 device unless otherwise noted.
August 17, 2010