NEC SpectraView Reference 271
Simon Baker, 3 February 2011

 


 

 

 

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Last August we carried out a full test of the professional grade NEC PA271W monitor. The screen provided a massive range of options and extras including some high end features such as hardware calibration support, a 14-bit 3D LUT, ColorComp uniformity correction and AmbiBright auto-brightness control. The screen performed very well in our tests, and we also took the opportunity to try out NEC's SpectraView II and SpectraView Profiler software packages which allowed varying degrees of calibration of the screen. You can read the full analysis in that review of course, so I won't repeat everything here.

In the review, we also discussed the other version of the screen which is available in Europe, and is referred to as the 'SpectraView Reference' or 'SV' edition of the screen. As we covered at the time, these models are designed for the European market and reportedly feature a few extras including hand-picked A-grade panels, some performance tweaks, a packaged monitor hood and most importantly, the support for hardware calibration via the European SpectraView Profiler software. The regular PA271W model is also available in Europe, but this SV package comes with some extra features for those really demanding users. We will carry out some further tests of this SV edition here, with particular focus on the hardware calibration. I won't carry out our full range of tests since results from our original review are still relevant when it comes to response time, office use, movies etc. We will also take a look at NEC's custom made wide-gamut colorimeter package (MDSVsensor2) which they supply for calibration of these screens.

Here's the spec of the PA271W-SV (as I will refer to it as for ease) screen:

Size

27"WS

Colour Depth

1.07 billion colour panel (10-bit), 14-bit 3D LUT with 4.3 trillion colour palette.

Aspect Ratio

16:9

Colour Gamut

102% NTSC colour gamut (97.1% Adobe RGB, 100% sRGB)

Resolution

2560 x 1440

Viewing Angles

178/178

Response Time

7ms G2G (12ms ISO)

Panel Technology

p-IPS

Contrast Ratio

1000:1 static

Interfaces

DVI x2 (with HDCP), DisplayPort

Brightness

300 cd/m2

Colour

Black bezel, base and stand

Special Features

Tilt, swivel, rotate and height adjustment. USB 2.0 ports (2 up, 3 down), Picture In Picture (PiP), Picture By Picture (PbP), programmable 14-bit 3D LUT, ColorComp, AmbiBright ambient light sensor, monitor hood

Buy

PCBuyIT.co.uk


Above: Front views of the screen with hood attached. Click for larger views

The PA271W-SV is obviously the same as the regular edition in terms of appearance so I won't go over it in too much detail again. You can read our PA271W review for more information. I have provided some images here of the screen with the calibration hood attached. This is packaged with the SpectraView Reference version of the screen but you must clip the sections together and assemble it yourself. There is a very good range of ergonomic adjustments available from the stand and a reasonable range of interface options with DVIx2 and DisplayPort. HDMI is missing sadly.

Although it is not provided as standard, NEC do offer a colorimeter calibration package for use with this screen. The monitor is packaged with their SpectraView Profiler software, something we will test later. However, NEC have produced a customised X-rite i1 Display 2 colorimeter for use with their wide gamut screens. This is referred to as the MDSVSensor2 (Medical Display SpectraView Sensor 2) device and again we will test this a little later on. This has been specially calibrated for use with their wide gamut displays including the PA series, so should offer a high level of performance.

The screen is also packaged with an individual display certificate confirming the screen meets the SpectraView Reference 271 standards. The certificate which came with our sample screen stated it had been tested with a Gretag Eye One (meaning X-rite i1 Pro presumably), and met various criteria and standards. It does also state that settings are native and recommends you calibrate to your individual needs.

State

Power Usage (W)

Factory Default

99.2

Calibrated Settings (Hardware Calibration)

83.9

Standby

1.9

We tested the screen at factory settings and once calibrated (see calibration section). At default settings, and without external USB devices connected, the screen used 99.2W of power. After calibration, when the screens brightness was automatically controlled through the hardware calibration to achieve the target 120 cd/m2 luminance, the power consumption was 83.9W. In standby the screen uses only 1.9W which is good.

More images, OSD menu information and product details are covered in our PA271W review

 


Colour Accuracy, Black Depth and Contrast

The Panel

The NEC PA271W-SV utilises a 10-bit (8-bit + AFRC) 'performance IPS' (p-IPS) panel. This is a name given by NEC to the high end 10-bit IPS panels being used in their PA series of screens, but technically the panel remains the same as the so called H-IPS panels in terms of pixel structure. It's still an H-IPS panel produced by LG.Display (the same LM270WQ2 module as used in the Dell U2711 in fact), but NEC have chosen to refer to it as a 'performance IPS' panel, hence the p-IPS. Technically this is an 8-bit panel with Frame Rate Control on the panel side to boost the colour depth to 1.07 billion colours. 10-bit support does require an end to end "10-bit journey" however so it is not always possible to put this into practice. Have a read of this article which discusses it in more detail.

It's all very well saying a panel is capable of 10-bit colour depth (1.07 billion colour palette) as opposed to an 8-bit colour depth (16.7 million colours), but you need to take into account whether this is practically useable and whether you're ever going to truly use that colour depth. Apart from the requirements of your application, operating system, graphics card and software, one more pertinent limitation is from a display point of view, where there must be an interface which can support 10-bit colour depth. Thankfully the PA271W-SV does include a DisplayPort interface capable of handling a 10-bit colour depth. If you use the DVI interface you can only take advantage of 16.7 million colours.

14-bit 3D LUT

Regardless of whether you have a true 10-bit colour depth being displayed, a screen with 10-bit capabilities still has its advantages. The monitor should still be capable of scaling the colours well, even from 24-bit sources. Most of these 10-bit panels will also be coupled with extended internal processing which will help improve accuracy and these are better translated onto a 10-bit panel than they would be onto an 8-bit panel, giving less deviation and less chance of banding issues. Simple LCD monitors work with internal signal processing with 8-bit accuracy (256 steps per primary colour). Depending on the desired white point the intensity of one or more channels must be reduced considerably. This can result in a considerable loss in the amount of steps in the colours that have been reduced and this in a loss of display quality. The result is posterization. Highlights and shadows can also be affected.

The PA271W-SV offers a programmable 14-bit 3D LUT to help offer smooth gradients and provide clarity in subtle detail. As well as being 14-bits per channel, the LUT is described here as being 3D. Whereas a typical 1D LUT adjusts colour on separate tables for each red, green, and blue, a 3D LUT accomplishes this on a single, mixed-colour cubic table. A 3D LUT improves the monitor's additive colour mixture (combination of RGB), a key factor in its ability to display neutral grey tones. This 14-bit LUT means that you have a palette of 4.3 trillion colours when using 10-bit panel capability (DisplayPort), or 65 billion when using DVI.

Colour Gamut

Like many modern displays, the screen uses enhanced W-CCFL backlighting and can offer a colour gamut covering 102% of the NTSC colour space. This also covers 97.1% of the Adobe RGB and 100% of the sRGB gamut. The screen offers sRGB and Adobe RGB emulation modes as well which we will look at shortly.

 

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 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 with the black triangle representing the display

  • 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.


It should be noted that I manually disabled the ColorComp uniformity adjustment and Metamerism setting for these tests. All other settings were left at default

Default settings of the screen were as follows:


NEC PA2471W-SV - Default Factory Settings (Adobe RGB mode)

Monitor OSD Option

Default Settings

Brightness

160

Contrast

---

Preset Mode

Adobe RGB (1)

White Mode

6500k

 

 

Default Settings

luminance (cd/m2)

164

Black Point (cd/m2)

0.19

Contrast Ratio

863:1

Default settings of the screen were tested first and unlike the regular PA271W model, the default preset mode of this screen is the Adobe RGB emulation mode. This mode is designed to slightly restrict the screens native gamut, and bring it in line with the Adobe RGB reference which is popular in the photography and professional image editing world. The results of this default test were mixed. Gamma and colour temperature were well set up and very close to the targets, being only 1% and 3% out respectively. Unfortunately default luminance of the screen was a little too high, although not overly bright or uncomfortable, being measured at 164 cd/m2. This gave us a black depth of 0.19 cd/m2, and a very good static contrast ratio of 863:1. The colour space coverage recorded by the i1 Pro Spectrophotometer was very close to the Adobe RGB reference as well, being only a little short in green shades. Compared to the standard full gamut of the screen (which you can see in the 'High Bright' and 'Full' preset modes below), the red coverage had been reduced a fair bit to bring it into the reference space.

Colour accuracy was actually not that great sadly, and perhaps we'd have hoped for a little more from a professional grade screen. I suppose those buying this SV edition are certainly going to want to carry out a full hardware level calibration and will have access to a decent hardware calibration device. We'd seen an average dE of 2.5 from the regular PA271W in this preset mode at factory settings, but on the PA271W-SV it was a little worse at 3.9. This ranged up to a maximum dE of 9.9. You will certainly want to carry out a calibration of the screen to obtain a better colour accuracy in this mode.

 


NEC PA2471W-SV - Default
sRGB Mode

Monitor OSD Option

Default Settings

Brightness

80

Preset Mode

sRGB (2)

White Mode

6500k

 

Default Settings

luminance (cd/m2)

84

Black Point (cd/m2)

0.10

Contrast Ratio

860:1

The default settings of the sRGB emulation mode were however much better and remarkably good. The emulation mode produced a restricted colour space which almost perfectly matched the sRGB reference as recorded by the i1 Pro. Gamma was slightly out in this mode with a reading of 2.3 (3% deviation). White point was again within 3% of the target at 6323k, but luminance was this time too low at only 84 cd/m2. This gave us a low black depth of 0.10 cd/m2 and a static contrast ratio of 860:1 which matched the Adobe RGB preset mode. Colour accuracy was excellent in this preset mode, with a seemingly well calibrated starting point. This gave us a dE average of 0.5 and a maximum of 1.4 which was very good. Calibration could correct the slightly offset gamma and colour temperature but the colours were already very accurate in this mode which was pleasing.

 


NEC PA2471W-SV - Default
High Bright Mode

Monitor OSD Option

Default Settings

Brightness

220

Contrast

---

Preset Mode

High Bright (3)

White Mode

Native

 

Default Settings

luminance (cd/m2)

226

Black Point (cd/m2)

0.25

Contrast Ratio

906:1

The 'High Bright' preset was just that - far too bright at factory settings! The OSD menu brightness control was set at 220 which yielded a luminance of 226 cd/m2 which would definitely need adjusting to make it more comfortable. Gamma was a little off again at 2.3 (3% deviance), and white point was 5% out at 6814k. As you can see from the colour space CIE diagram, the red coverage was a little wider than the Adobe RGB emulation mode had achieved, with the monitors black triangle stretching now to cover the full range of the backlight's gamut. In this mode black depth was 0.25 cd/m2 which gave us a slightly better contrast ratio of 906:1. This preset mode seemed to return the best contrast ratio. Colour accuracy was unfortunately more like the Adobe RGB mode again, with average dE of only 3.3 and maximum of 8.1. Again calibration would be needed to return better colour fidelity.

 


NEC PA2471W-SV - Default
Full Mode

Monitor OSD Option

Default Settings

Brightness

160

Contrast

---

Preset Mode

Full (4)

White Mode

6500k

 

Default Settings

luminance (cd/m2)

164

Black Point (cd/m2)

0.20

Contrast Ratio

834:1

The last mode we wanted to test was the 'Full' mode which utilises the monitors full native gamut. I've provided the CIE diagram of the gamut compared with the sRGB reference above as we had compared it with the Adobe RGB reference in the 'high bright' report. Gamma was only 2% out now with an average of 2.2. White point was a little further off at 6114k (6% out) and luminance was again a little too high at 164 cd/m2. This was not as severe as the high bright mode at least. With a black point of 0.20 cd/m2 we had a static contrast ratio of 834:1 which was slightly lower than the Adobe RGB / sRGB emulation modes, and a bit further off from the high bright mode which had returned 906:1. Colour accuracy was again poor sadly at 4.1 dE average / 11.6 maximum.

 

 

Software Calibration Results

 

 

 

I wanted to calibrate the screen in each of the main preset modes 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 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.

 

Please remember that these are all software based graphics card profiling "calibrations" as opposed to hardware level true calibration which we will come onto shortly. These are the normal calibration methods we use for our monitor reviews which creates a profile which is activated at a software level in the graphics card. This is more than adequate for most users and is all you really need for nearly all the mainstream monitors anyway. In fact, most don't even have the option for hardware level calibration, so you have to make do with software profiling only. For professional use and high end colour work these kind of profiles, although good, are not acceptable. You need full hardware calibration which can make adjustments at a hardware level and to the monitors extended internal LUT. This is what the high end professional market need and want from a screen. The PA271W-SV offers the hardware capabilities to do this form of calibration as well, which we will come onto shortly.

 


NEC PA271W - Software Calibrated Settings - Preset Mode '
Adobe RGB'

Monitor OSD Option

Adjusted Setting

Brightness

120

Contrast

---

Preset Mode

Adobe RGB (1)

White Mode

6500k

 

Calibrated Settings, 'Adobe RGB' Mode

luminance (cd/m2)

120

Black Point (cd/m2)

0.15

Contrast Ratio

824:1

 

Calibration in the Adobe RGB preset mode was a good change from default settings. Colour temperature was less than 0.5% deviation now at 6496k, and gamma was an average of  2.2 being only 1% out. These settings had already been good at default anyway. Colour accuracy was significantly improved, with dE average now 0.5 (down from 3.9 at default). dE maximum was also only 1.2 (down from 9.9) which was again a great result. LaCie would consider colour fidelity to be excellent across the whole range. This was a very good result and exactly what you would expect and hope for from a high end screen such as this. Black depth was still very good at 0.15 cd/m2 giving us a static contrast ratio of 824:1. This shows calibration in the Adobe RGB preset can produce some very good results if you want to work in this colour space more closely. Our calibrated settings and profile are available if you want to try them on your PA271W-SV screen in our ICC profile database.

 


NEC PA271W-SV - Software Calibrated Settings - Preset Mode
'sRGB'

Monitor OSD Option

Adjusted Setting

Brightness

120

Contrast

---

Preset Mode

sRGB (2)

White Mode

6500k

 

Calibrated Settings, 'sRGB' Preset Mode

luminance (cd/m2)

120

Black Point (cd/m2)

0.14

Contrast Ratio

828:1

 

I calibrated the screen in the sRGB preset mode as well. The gamma, colour temperature and luminance targets were met almost spot on in every case. This process had improved the default luminance of 84 cd/m2 through the adjustment of the OSD brightness control to 120. Contrast was retained as well and at 828:1 was very similar to the Adobe RGB mode. Colour accuracy had improved ever so slightly from the already excellent default settings, now down to 0.4 / 1.2 (from 0.5 / 1.4). This preset can be used if you want to work in the more restricted sRGB colour space and the emulation is very good here. Again, ICC profile available if you want it in our ICC profile database.

 

 


NEC PA271W-SV - Software Calibrated Settings - Preset Mode '
High Bright'

Monitor OSD Option

Adjusted Setting

Brightness

125

Contrast

---

Preset Mode

High Bright (3)

White Mode

Native

 

Calibrated Settings, 'High Bright' Mode

luminance (cd/m2)

120

Black Point (cd/m2)

0.14

Contrast Ratio

857:1

 

I then set the screen in its 'High Bright' mode. White mode (colour temperature) was left in 'Native' mode as per the default settings which we had already established was very close to the target of 6500k in this preset.

 

Calibration was a great success. Gamma had already been quite accurate at default factory settings (2.3) but was corrected to the target of 2.2 after calibration as one would hope. Colour temperature was excellent at 6522k (<0.5% out) although this was already good out of the box in the native mode (5% out). Luminance was now a perfect 120 cd/m2 with OSD brightness set at 125. This gave us a good black depth of 0.14 and contrast ratio of 857:1. Best of all, colour accuracy was now excellent, with average dE at 0.4 and maximum only at 1.5. This was improved significantly from the default of 3.3 average / 8.1 maximum in this preset mode. You can use our settings and calibrated ICC profile on your PA271W-SV as well if you want. See our ICC profile database for more information.

 


NEC PA271W-SV - Software Calibrated Settings - Preset Mode 'Full'

Monitor OSD Option

Adjusted Setting

Brightness

120

Contrast

---

Preset Mode

Full (4)

White Mode

6500k

 

Calibrated Settings, 'Full' Preset Mode

luminance (cd/m2)

120

Black Point (cd/m2)

0.15

Contrast Ratio

820:1

 

I changed back to the 'Full' preset mode and calibrated the screen. Again, this produced pleasing results in most regards. Gamma was spot on at 2.2 average. Colour temperature was now 6513k, being only <0.5% out from the target of 6500k. This corrected the 6% deviation we saw in colour temperature at default settings in this preset. With a luminance at 120 cd/m2 as hoped, black depth was a very good  0.15 cd/m2, giving a slightly lower static contrast ratio than we had reached in the 'High Bright' mode of 820:1 but in keeping with the Adobe RGB and sRGB modes. This was a similar pattern to what we saw in the default high bright vs. full modes. Colour accuracy was again corrected very nicely, with dE average of 0.4 (down from 4.1 default) and a maximum of only 1.3 (down from 11.6). The colour accuracy matched the calibrated 'High Bright' preset,  and so both were very good in this regard. I'd recommend using the 'High bright' mode instead of the 'full' mode to achieve the best results from a graphics card LUT correction perspective as it offers a slightly better contrast. If you want a smaller colour space the Adobe RGB and sRGB modes work very well too. Again, ICC profile available if you want it in our ICC profile database.

 

 

 

I tested the screen using various colour gradients in all of these preset modes which showed smooth transitions and no apparent banding. There was some slightly noticeable gradation in darker tones which I would expect are eliminated if you can take advantage of the 10-bit panel depth (8-bit +AFRC). Unfortunately I do not have the means to fully test the 10-bit capability of the p-IPS panel.

 

 

 

Hardware Calibration Results

 

We also now wanted to test the calibration performance of the screen with the LaCie software carrying out full hardware level alterations to the monitors LUT. This was not possible with the regular PA271W when we tested it, but with the combination of the SV edition of the screen, and LaCie's latest v4.5.6 software we could make these changes.

 

 

When you carry out the process, the software detects you have a compatible monitor and you will notice in the above screen shot that it includes a section verifying that it is connecting to the monitor. I carried out the calibration using the i1 Pro spectrophotometer which took around 10 mins 15 seconds to complete. Afterwards I verified the calibration using the normal test and report function.

 


NEC PA271W-SV - Hardware Calibrated Settings

LaCie Blue Eye Pro + i1 Pro Spectrophotometer

Monitor OSD Option

Adjusted Setting

Brightness

n/a

Contrast

---

Preset Mode

SpectraView II (5)

White Mode

n/a

 

Calibrated Settings,
Hardware LUT

luminance (cd/m2)

120

Black Point (cd/m2)

0.16

Contrast Ratio

765:1

 

Once the LaCie software detects you have a compatible monitor it automatically switches to the programmable preset mode (number 5) which gets named in the OSD menu as 'SpectraView II', after NEC's own software. As you can see, the calibration was a great success, reaching the targets very accurately. Contrast was a little lower than the software calibrated tests, now being 765:1 (as opposed to ~825:1). dE was now 0.4 average and 1.5 maximum which was very pleasing. We will talk more about the benefits of hardware calibration and take a look at NEC's own software in the following sections.

 

 

 

SpectraView Profiler

 

To take full advantage of the screen for calibration and profiling, NEC have built in a hardware calibration feature which allows you to make corrections to the monitors 14-bit 3D LUT. This can provide even better colour accuracy and allows you to store your calibration in the screens hardware. Professional markets and those working with colour critical content require this kind of high end hardware calibration so this is one of the reasons this screen separates itself from the more mainstream models. NEC have their own specific software for this hardware calibration which is called SpectraView. There are actually two versions of this software, both offering different capabilities in terms of the calibration possible.

 

 

 

In Europe the "SpectraView Profiler" software is provided by BasICColor who offer a free 14 day license for the full version of the software. After speaking with NEC Europe to clarify we discovered that this software allows three levels of calibration of the PA series, depending on whether you have bought the regular PA monitor or the special SpectraView II edition in European countries. The latter is referred to over here as the NEC PA271W-SV or the 'SpectraView Reference 271". It comes at a higher cost but is aimed at users who require that extra level of specialist performance and high end professional application. I would like to emphasise that there are significant differences between the regular PA271W and the SV edition of the screen, something which every NEC representative highlighted to me during our conversations.

 

The SV model in Europe was produced in addition to the regular PA model because of the high demands of the European market and the expectations they have when it comes to high end professional screens. NEC therefore offer the SV version which include panels which have reportedly been hand picked and selected to be the absolute top end in terms of dE performance, gamma correction etc. These are then tuned and altered to enhance the performance even further, with advanced adjustments being made in the factory to ensure these are the absolute cream of the crop. The SV model is then packaged with a calibration hood, SpectraView Profiler software and a factory report validating the performance of the panel selected and confirming the tuning completed. It is not packaged with a hardware colorimeter in Europe so you would need to already own one or plan to purchase one for proper calibration. The SV models do come with a 6 month pixel defect guarantee as well. The normal PA version does not go through this extra process and does not come with the additional extras.

 

Also, importantly for calibration the PA271W regular edition and PA271W-SV have a slight firmware difference which allows for different levels of calibration. The PA271W only allows you to use the European software to calibrate at a software (graphics card LUT) level alone, or at a hard/software level which also controls limited monitor settings such as brightness and the RGB channels automatically. It does not however control the monitors 14-bit LUT and the option for "hardware calibration" within the software is greyed out. If you purchase the SV version of the screen, the firmware communicates with the software automatically and the software will then allow full calibration of the monitor's LUT. We of course have the SV edition of the screen here so we are able to test the full hardware calibration with this software now. I would also note that the SV Profiler software communicates with the SV edition of the screen and will not request you to install a license file or anything. It knows you are using the SV screen and the software just works.

 

 

 

I installed the latest version of the SpectraView Profiler European software which was v4.1.24 and I'll give you a quick tour as well as some calibration results. When you load up the software you are presented with various options which you can configure before carrying out a calibration of your screen. The information section confirms your current active profile (here just showing one I had just made with LaCie's software) along with your defined calibration targets. You can select the device being used to calibrate the screen from the top left, and here we have selected the i1 Pro Spectrophotometer.

 

 

Entering the settings menu gives you a whole range of options. I won't go through them all as they are self explanatory really. You will see that within the 'presets' section you can choose the calibration method. As I've already explained, full hardware calibration is now available as we are using the SV edition of the screen so I have selected it here. Within the luminance/contrast ratio section you can set the targets for white and black, as well as do a quick simple measure of the current settings. You will see here that we are aiming for 6500k white point, 2.2 gamma and 120 cd/m2 luminance. Settings can be defined in the menu on the left. We took a look at a few more sections of this software in our PA271W review, so I won't repeat them here. I entered the calibration section on the left and proceeded with the process to calibrate the screen at a hardware level.

 

The screen automatically enters a preset mode which is labelled as 'programmable 3'. The brightness and RGB settings are then not available for manual adjustment in the OSD as the software has controlled these while calibrating. The process itself takes around 8 mins 40 secs to complete using the i1 Pro, with the sample window displaying the usual white, black, grey and coloured images in front of the colorimeter in order to adjust white point, luminance, grey balance etc. The entire process was automatic, including adjustments of the backlight (brightness setting), RGB channels and full adjustments to the monitors 14-bit 3D LUT.

 

 

At the end you are presented with the above screen which confirms the screen has been calibrated successfully. There is an option there to further validate the results which will give you more measurements. A note I would like to make is that the contrast ratio and black depth measurements shown here may not be reliable as the i1 Pro has a measurement limit at the low end of 0.20 cd/m2 and so we will validate these readings using an i1 Display 2 colorimeter (which can measure down to 0.02 cd/m2 with accuracy) in our tests in a moment, using our usual LaCie reports. For now, ignore the black depth and contrast ratio measurements from the SV Profiler software as the i1 Pro is too limited at the lower end, and we are using that device to carry out this calibration.

 

Note: From what I could tell, the SV Profiler software does not allow you to change any of the monitor OSD settings from within it. If you carry out this calibration it will enter you into the Programmable preset mode. The default ColorComp (uniformity compensation) setting for this preset is "level 5" and within the Programmable preset mode, you cannot change this in the OSD, even from the advanced menu section. So what I'm saying is, if you calibrate using this software you will be stuck on ColorComp level 5 normally. This does improve uniformity (see further down) but does negatively impact contrast ratio. To overcome this, you need to enter into the SV II software which we will look at in a moment, which does allow you to change the monitor settings from within it. Here you can turn off the ColorComp within the Programmable preset mode. The results above and below are based on ColorComp having being turned off first, so as not to impact contrast ratio.

 

 

 

 

The validation process presents you with a summary report like the above. As you can see, this report now includes details dE information relating to colour accuracy. Average dE was recorded at 0.20, with maximum of only 0.46. Colour fidelity would be considered excellent all round, and the calibration seemed to offer excellent results. You may notice that the contrast ratio / black point recorded here in this validation is significantly less than the initial report above (which gave us a contrast ratio of 858:1). This discrepancy can probably be put down to the low light accuracy of the i1 Pro which doesn't really read below 0.20 cd/m2 properly. I will validate the results again using the i1 Display 2 colorimeter in a moment but as I've already said, ignore the black depth/contrast ratio measurements from the SV Profiler software for now. There is also a report showing the chromaticity and gamut of the screen accessible through the 'window' sub-menu of the software which I've included above.

 


NEC PA271W-SV - Hardware Calibrated Settings
SpectraView Profiler + i1 Pro Spectrophotometer

Monitor OSD Option

Adjusted Setting

Brightness

n/a

Contrast

---

Preset Mode

Programmable 3 (5)

White Mode

n/a

 

 

Calibrated Settings, SpectraView Profiler Euro

luminance (cd/m2)

119

Black Point (cd/m2)

0.15

Contrast Ratio

773:1

 

I ran the LaCie test and report feature on our newly calibrated profile to see what it thought of the results as well. Obviously there will be some deviation between different sets of software and it's probably arguable which is more accurate here anyway, but I include it for reference since we have used it throughout all our reviews and tests. The LaCie report confirmed the results shown from the SpectraView Profiler package. Gamma, colour temperature and luminance were all corrected nicely. We had a black depth of 0.15 validated by the i1 Display2 colorimeter, giving a contrast ratio of 773:1 which is only a little less than the software calibrated profiles we'd created in the 'Full', Adobe RGB and sRGB preset modes (~820:1). Colour accuracy was confirmed to be very good with average dE of 0.5. Maximum was listed up to 1.3, but overall an excellent and impressive result. Colour gradients were very smooth with no visible banding or issues.

 

For more information about this software you may also want to see our PA271W review

 

 

 

 

SpectraView II

 

 

The other thing I wanted to take a look at is the USA version of the SpectraView II software, available from NEC's US website. We tested this with the PA271W before and this software does allow hardware level calibration of both the regular and SV editions of the screen. The European SpectraView Profiler software can only carry out full hardware calibration when combined with the SV version of the screen, but the US SpectraView II software can work with either fine. This is an NEC in-house piece of software.

 

 

I first updated to the latest v1.1.07 of the software and then loaded it up for testing. The above confirms the changes made in the latest version for those interested. The addition of control over the colour gamut is an interesting new feature which I'll test in a moment.

 

 

I won't go over all the options and features of this SV II software again as we covered it in detail in our PA271W review if you want to know more. We defined our target settings as normal and within the settings we opted for the highest possible accuracy using 52 steps for profile creation and selecting best grey scale colour tracking as the calibration priority. You will see from the above screenshot that NEC have added a function to define the target colour gamut, which includes options for sRGB and Adobe RGB. For now I will calibrate with full native gamut, but will test some other options afterwards. We did also disable the ColorComp feature accessible through this software. As far as we can tell, this is the only way you can control the ColorComp for the 'SpectraView / programmable' preset mode as it cannot be controlled via the OSD menu once the screen has entered this preset.

 

  

 

The left hand image confirms your target settings for the calibration. As with other software packages, if you use the i1 Pro it must first be calibrated to a zero point using the provided white tile stand. The SV II software asks you to do this (right hand image) as you set everything up or before you start a calibration of your monitor.

 

 

I restored my graphics card and screen to default settings to perform a calibration with the SpectraView II software. As you follow through the calibration process you are prompted to place your calibration device in the centre of the screen to begin. A fairly small sample circle appears to carry out the calibration behind where you have placed the device. The rest of the screen is black and a progress indicator is shown in the top left hand corner like the one above. This shows you an overall progress as well as various steps to adjust brightness, white point etc. At a setting of 52 steps this whole process took around 2 minutes 30 seconds to complete with the i1 Pro, but is all automated.

 

 

As with the European software, the whole process is automated and the screen automatically enters into the "5" preset mode which is then named 'SpectraView II'. The options in the brightness and RGB menus are then not available. Like the Euro software, the package makes these adjustments for you as well as a full adjustment to the internal 14-bit LUT. As a reminder, that is only possible with the Euro software when using the SV version of the screen as we have here, and not with the regular PA271W model.

 

 

At the end of the process you are presented with the above summary screen. It confirms your calibrated settings and the tabs in this screen can be used to validate other aspects of the calibration. Again ignore the black depth / contrast ratio measurements presented here as there are limitations with the i1 Pro at the lower end. I will test these in the LaCie reports using an i1 Display 2 instead.

 

 

The colour gamut is also shown relative to a selected reference colour space, in this instance shown by the blue triangle of the sRGB colour space.

 

 

The gamma curves are also available showing the target and calibrated results. In this instances the lines are very accurate showing a good calibration result.

 

 

The color tracking tab gives you a report of the greyscale deltaE achieved. On average dE was 0.57, ranging up to 0.89 maximum. A very good result. I will run LaCie's test and report as well to see what that software thinks of the calibrated state.

 


NEC PA271W-SV - Hardware Calibrated Settings
SpectraView II + i1 Pro Spectrophotometer

Monitor OSD Option

Adjusted Setting

Brightness

n/a

Contrast

---

Preset Mode

SpectraView II (5)

White Mode

n/a


 

 

Calibrated Settings, SpectraView II USA

luminance (cd/m2)

120

Black Point (cd/m2)

0.16

Contrast Ratio

756:1

 

Again LaCie's software confirms the calibration was a great success with all targets met very well. Validation with an X-rite i1 Display 2 colorimeter allowed us to measure a black depth of 0.16 cd/m2 which gave us a static contrast ratio of 756:1. This was very similar to the results we'd achieved with the SV Profiler software (773:1) but a little lower than our software calibrated profiles, 857:1 being the highest when in the 'high bright' preset. This was still a respectable performance though. Colour accuracy was confirmed as being excellent, with average dE of 0.4 and maximum of 1.2. Again this SV II software can produce very good results and is simple and easy to use.

 

For more information about this software you may also want to see our PA271W review

 

 

Calibrating Colour Spaces

 

  

 

We have tested the software calibration using the i1 Pro and LaCie's software in each of the standard preset modes of this screen - High Bright, Full, Adobe RGB and sRGB. All returned accurate results once they had been profiled at a software level and through the creation of an ICC profile for the graphics card. The sRGB and Adobe RGB modes also gave us a decent emulation of the smaller colour spaces which is very useful for those who need to work with anything other than the full native gamut (102% NTSC coverage). When we hardware calibrated the monitor using the i1 Pro again, the NEC Profiler software does not allow you to define anything other than the native gamut of the screen for your target. The software will allow you to successfully calibrate the internal hardware LUT to a high standard, but you cannot do so while also using a smaller colour space such as Adobe RGB or sRGB. Until now, the same could be said for NEC's SpectraView II software. However, as we covered briefly in the SpectraView II section of this review, NEC have now introduced an option in their latest v1.1.07 software to define the target colour space as well.

 

 

You can define the target colour space within the 'edit > target' menu. You can see the options available above, and we will test the sRGB and Adobe RGB here as they are both common standards.

 

 

You can even edit each of these colour spaces at a very precise x/y level for each of the RGB channels for absolute calibration accuracy. For now we will stick with the pre-defined sRGB and Adobe RGB targets in the software. I followed the process through as before and all changes were automated, with the screen entering into the 'SpectraView II' mode in the OSD menu.

 

 

sRGB Gamut - I first calibrated to the sRGB gamut. The above report confirms the results of the calibration. As before, ignore the black level / contrast ratio figures here as the i1 Pro is not reliable enough and the numbers are skewed a lot. I will validate in the final LaCie report using an i1 Display 2 to get an accurate contrast figure. This report confirmed the white point (colour temperature) was calibrated to 6510k so almost spot on to the target.

 

 

The colour gamut tab confirms that the calibration had successfully set the screen at a hardware level to the sRGB colour space. This was a very welcomed addition to the software and it should now allow you to carry out a full hardware LUT correction with a defined colour space of your choosing.

 


NEC PA271W-SV - Calibrated Settings - sRGB Colour Space
SpectraView II + i1 Pro Spectrophotometer

 

 

Calibrated Settings, SpectraView II sRGB

luminance (cd/m2)

119

Black Point (cd/m2)

0.16

Contrast Ratio

759:1

 

As you can see, the LaCie report confirms the reduction in the colour space to sRGB as we had hoped and was identical to that we obtained from the monitors standard sRGB emulation mode. All other targets were met nicely, although the colour accuracy was not quite as low as we had seen when hardware calibrating to the native gamut. This could be minor software discrepancies of course, but the results were still very good, with a dE average of 1.0 here. We validated the black depth with an i1 Display 2 which returned us a static contrast ratio of 759:1, practically the same as we'd seen from the SV II calibration at native gamut.

 

 

 

Adobe RGB Gamut - I went back into the target settings and defined the Adobe RGB colour space as our target for the next calibration.

 

 

Again, you can manually adjust the parameters if you wish or need to tweak anything.

 

 

The report after the calibration confirms the white point was again very accurate at 6525k. This time black depth and contrast ratio were not even listed, an indication that the i1 Pro is struggling at the lower end. Again I'll confirm these figures in the LaCie report in a moment.

 

 

The colour gamut tab confirms the colour space has been matched to the Adobe RGB reference. We will test this calibrated state with the LaCie software as well now.

 


NEC PA271W-SV - Calibrated Settings - Adobe RGB Colour Space
SpectraView II + i1 Pro Spectrophotometer

 

 

Calibrated Settings, SpectraView II Adobe RGB

luminance (cd/m2)

123

Black Point (cd/m2)

0.16

Contrast Ratio

784:1

 

Again the colour space has successfully been reduced to be much closer to the Adobe RGB reference. The colour space of the monitor here (black triangle) matches the report from the preset Adobe RGB emulation mode exactly, so again this target in the SV II software had reached the same colour space successfully. The other targets were met nicely, although there was some slight variance in gamma (3%) and white point (2%) perhaps down to a difference between the software. Colour accuracy was again confirmed as very good at 0.7 dE average. Again, not quite as low as the hardware calibration at native gamut, but still excellent. The i1 Display 2 confirmed contrast ratio was 784:1, again very similar to the hardware calibrated native gamut and sRGB gamut modes.

 

Once calibrated it is easy enough to switch between the colour spaces from within the SV II software without needing to go through the whole calibration process again. You just choose your target settings from the drop down box, and those with a green tick next to them show they have been calibrated. The screen changes to the different state (and colour space) quickly and you're away.

 

 

 

NEC Wide Gamut Colorimeter - MDSVSensor2

 

 

As an optional extra, NEC offer a special colorimeter package for use with the PA series of screens (and other wide gamut monitors in their range). This device is referred to as the 'MDSVSensor2' (Medical Display SpectraView Sensor 2) and is a customised X-rite i1 Display 2 colorimeter. Unlike standard i1 Display 2 devices, which are set up for use with standard gamut screens, this NEC device has been optimised for use with NEC's wide gamut displays. On the front is an NEC logo and a sentence explaining it has been "custom calibrated for wide-gamut NEC displays". Apart from that it looks like a regular i1 Display 2. The customised device has been programmed internally with correction matrices for use with NEC's wide gamut displays. As such it has been tweaked to offer compatibility and accuracy with these screens.

 

1) SpectraView Profiler Software - We wanted to test this device with the PA271W-SV, again using the SpectraView Profiler software. This time within the settings menu we selected the i1 Display 2 device and set the usual targets for calibration. ColorComp was again disabled from within the SV II software as we talked about earlier, as with this enabled it can impact contrast.

 

 

The calibration was carried out with full hardware LUT adjustments and was totally automated as before. At the end we were presented with the above summary report. We went into the validation function to get more detail:

 

 

As you can see, the calibration was a great success. Since we were now using the i1 Display 2 we could rely on more accurate low level readings and so the black depth (0.16) and contrast ratio (739:1) recorded here were reliable. The other targets were met very well also and dE was very similar to the calibration using the i1 Pro had been. Average dE was 0.24 (0.20 with i1 Pro) and maximum was 0.72 (vs. 0.46). Very close of course, but it does go to show that the device works very well with this screen.

 


NEC PA271W-SV - Hardware Calibrated Settings
SpectraView Profiler +  NEC i1 Display 2



 

Calibrated Settings, SpectraView Profiler

luminance (cd/m2)

119

Black Point (cd/m2)

0.16

Contrast Ratio

748:1

 

The LaCie software confirmed the results were indeed very good. Targets were met nicely, and contrast ratio was also recorded here at 748:1. This was pretty much the same result as we had achieved with the i1 Pro + SpectraView Profiler hardware calibration (773:1). We had achieved up to 857:1 through software calibration but this hardware calibration is obviously far more accurate and I suspect the contrast is sacrificed a bit for better grey scale tracking and finer adjustments to the LUT. Colour accuracy was confirmed as being excellent again, actually being ever so slightly better than the readings from the i1 Pro tests (0.3 vs 0.5 and 1.1 vs 1.3). This slight different could of course be software discrepancies but the LaCie report does confirm the calibration was a great success.

 

 

 

2) SpectraView II Software - We also carried out a full hardware calibration using The USA SpectraView II software. We stuck with the full native gamut of the screen and followed the process through using the NEC i1 Display 2 device.

 

 

The above summary results confirmed targets were met well, with an accurate white point and a good contrast ratio achieved of 795:1. This was slightly higher than we had reached with the NEC SV Profiler software (~748:1) in fact. You will notice that the software identifies the calibration sensor as the NEC MDSVSensor (custom iOne Display v2).

 

 

The colour tracking tab confirms colour accuracy was again very good after calibration, with an average dE of 0.77 and maximum of 1.16. We had achieved slightly better results when using this software with the i1 Pro (0.57 dE average / 0.89 max) which is a similar pattern to what we saw when using the SV Profiler software. Nevertheless, calibration was excellent.

 


NEC PA271W-SV - Hardware Calibrated Settings
SpectraView II +  NEC i1 Display 2

 

 

Calibrated Settings, SpectraView II USA

luminance (cd/m2)

123

Black Point (cd/m2)

0.16

Contrast Ratio

771:1

 

The report from LaCie's software confirmed a good result. There was a slightly lower white point at 6348k than we had aimed for in the calibration, and colour accuracy was not quite as good as we had seen when calibrated with the i1 Pro device and SV II software (1.1 dE average here vs. 0.4 before). Contrast was confirmed as being 771:1 which is very similar to that achieved with the SV Profiler software and NEC colorimeter device.

 

 

 

3) LaCie Blue Eye Pro Software - I also carried out a hardware calibration using this device, but combined with the LaCie Blue Eye Pro software, again calibrating at a hardware level for maximum performance and accuracy.


NEC PA271W-SV - Hardware Calibrated Settings
LaCie Blue Eye Pro +  NEC i1 Display 2

 

 

Calibrated Settings, SpectraView II USA

luminance (cd/m2)

120

Black Point (cd/m2)

0.17

Contrast Ratio

705:1

 

Again the results of this hardware calibration were excellent. Targets were met very well indeed. We did have a slightly lower contrast ratio when using the LaCie software of 705:1 but still this was good. Colour accuracy was excellent as well, with average dE of 0.3 and maximum of 1.2.


 

 

Conclusions - Overall I was pleased with the results obtained with the NEC customised i1 Display 2. It seems that when combined with a compatible screen like the PA series, the results obtained are actually very similar to the i1 Pro spectrophotometer. This is very impressive considering it's about a 10th of the price of course. Being set up and calibrated for use with a certain range of screens should ensure a high level of accuracy and so this would make a good solution for someone purchasing the PA271W-SV or another of the range and wanting to carry out calibration. If you're bothering to buy the SV version of the screen then you will want some calibration device certainly. Of course a high end spectrophotometer like the i1 Pro is more versatile for a wide range of devices, technologies, backlights and screens, but the i1 Display 2 is still a very capable colorimeter device at an affordable cost.

 

 

 

Calibration Performance Comparisons

 

I thought it would be useful to summarise the results from each of these preset mode calibrations in one place. The results of the SpectraView calibrations are recorded using the LaCie reports in order to keep all of these uniform:

 

Calibration Type and Instrument

Preset Mode / Software

Deviance from target (%)

Black depth
(cd/m2)

Contrast Ratio

Ave. dE

Max dE

Gamma

Colour Temp

Lum

Software LaCie
with i1 Pro

 

High Bright

0

0

0

0.14

857:1

0.4

1.5

Full

0

0

0

0.15

820:1

0.4

1.3

Adobe RGB

1

0

0

0.15

824:1

0.5

1.2

sRGB

0

0

0

0.14

828:1

0.4

1.2

Hardware + i1 Pro

LaCie Blue Eye

0

0

0

0.16

765:1

0.4

1.5

Hardware + NEC

LaCie Blue Eye

0

0

0

0.17

705:1

0.3

1.2

Hardware + i1 Pro

SV Profiler

1

0

1

0.15

773:1

0.5

1.3

Hardware + NEC

SV Profiler

0

1

1

0.16

748:1

0.3

1.1

Hardware + NEC

SpectraView II

1

2

3

0.16

771:1

1.1

2.7

Hardware + i1 Pro

 

SpectraView II

1

1

0

0.16

756:1

0.4

1.2

SV II - Adobe RGB

3

2

3

0.16

784:1

0.7

1.9

SV II - sRGB

2

0

1

0.16

759:1

1.0

3.6

 

  • Software Calibration - The software based calibrations using just the LaCie software and i1 Pro all produced very similar results. Remember, these are corrections only at a graphics card level, with minimal hardware changes made only through limited controls like brightness and RGB channels. This is the regular calibration which would be carried out on most mainstream monitors we test, since most do not offer hardware level calibration anyway. All preset modes offered excellent colour accuracy and all targets were met properly as hoped. The high bright mode seemed to offer a slightly higher contrast ratio (857:1 compared with ~825:1) but not by much. The Adobe RGB and sRGB emulation modes provided pretty accurate representation of the smaller colour spaces which was good.
     

  • Hardware calibration with LaCie - Once you allow the software to fully calibrate the internal LUT you are improving accuracy greatly. The process does take a long time at >10 minutes but does produce some excellent results. The results when using the i1 Pro with LaCie software were very similar to the results from the SV packages. The combination of the NEC puck and LaCie software did seem to return a slightly lower contrast ratio though for some reason. The puck is optimised to work with NEC's software so perhaps it doesn't perform quite as well without it.
     

  • Hardware calibration with SV Profiler - This software is very comprehensive and the results were again excellent. Remember, this is making adjustments at a hardware level to the internal 14-bit LUT so there is a far more accurate result produced. Both the i1 Pro and customised NEC i1 Display 2 devices produced excellent results which were pretty comparable. Targets were met well, although contrast does drop a little when the screen is hardware calibrated as opposed to software calibrated, to about 773:1. This is because of the added grey scale tracking and improvements to the whole accuracy which impact contrast slightly.
     

  • Hardware calibration with SV II - Again this software allows full hardware level correction, and even allows you to define a target colour space. The i1 Pro produced slightly better results than the NEC i1 Display 2 but both were very good. Again contrast was around 771:1 so slightly lower than the software calibrated profiles, but again with superior grey scale tracking and accuracy. The calibration to the smaller Adobe RGB and sRGB colour spaces worked very well and was an excellent new feature to the software.

 

I tested the screen with colour gradients in each of these calibrated preset modes. The gradients were very smooth and showed no sign of banding. I was unable to test the full potential of the 10-bit colour depth due to graphics card and software limitations but expect results will be even better if you can really put it into practice. There was some very slight gradation in darker tones in my gradient tests which is common to 8-bit displays.

 

 

Above I have plotted the colour accuracy reports from the NEC PA271W-SV against the results of other competing models in this range we have tested. For the purposes of these comparisons the measurements from the LaCie reports were all very similar. I have used the results from the software calibrated 'High Bright' mode here since that produced the best black depth / contrast ratio, and it is what we had used to plot the results of the regular PA271W before.

 

As you can see, default colour accuracy was moderate with average dE of 3.9. This was similar to the PA241W mode (4.2) but not as good as the very well factory calibrated regular PA271W (1.1). Once calibrated properly, colour accuracy is much better. At an average dE of 0.4 it offers excellent colour fidelity. Again keep in mind there is more to this than just a validation of a colour profile and colour accuracy reports, which does separate this screen from the more mainstream models. Needless to say the other high end features of this screen (and the PA series in general) like 3D 14-bit LUT's, hardware calibration, ColorComp etc separate it from the lower cost mainstream models you see it compared against when it comes to high end professional uses.

 

 

Calibrated black depth was actually very good here, and a big improvement over the regular PA271W model we tested. We recorded a black depth of 0.14 which was only bettered by the 23" PA231W in this comparison (0.13). This gave us an excellent static contrast ratio of 857:1, just behind the 912:1 of the PA231W. There was a big improvement over the regular PA271W which only reached 0.20 / 600:1. Perhaps NEC have tweaked the panel and backlighting operation in both models since its initial release, or perhaps this is one of the 'tweaks' they have made for the higher priced SV version. Either way, it's a welcomed improvement as previously this was a weakness of the PA271W. If you carry out a full hardware calibration as you would probably want to, the contrast ratio drops a little to around 770:1, which is still very good. ColorComp will also have an impact on the contrast ratio as we will test later.


 

 


Contrast Stability

I wanted to see how much variance there was in the screens contrast as we adjusted the monitor setting for brightness. In theory, brightness and contrast are two independent parameters, and good contrast is a requirement regardless of the brightness adjustment. Unfortunately, such is not the case in practice. We recorded the screens luminance and black depth at various OSD brightness settings, and calculated the contrast ratio from there. Graphics card settings were left at default with no ICC profile or calibration active. Tests were made using an X-rite i1 Display 2 colorimeter. It should be noted that we used the BasICColor calibration software here to record these, and so luminance at default settings varies a little from the LaCie Blue Eye Pro report. I carried out the following tests in the 'high bright' preset mode.

OSD Brightness

Luminance
(cd/m2)

Black Point (cd/m2)

Contrast Ratio
( x:1)

400

382

0.38

1000

350

381

0.38

1002

300

324

0.32

1012

250

269

0.27

996

200

217

0.22

984

150

164

0.16

1025

130

143

0.14

1019

110

122

0.12

1013

90

100

0.10

1002

80

89

0.09

983

60

66

0.09

733

40

44

0.09

489

 

Luminance Adjustment Range = 338 cd/m2

Black Point Adjustment Range = 0.29 cd/m2

Average Contrast Ratio (backlight only) = 1004:1

 

There's a few things I wanted to talk about here. First of all, the OSD brightness control is listed in cd/m2 as opposed to a percentage, and allows you to control the range from a maximum setting of 400 cd/m2 all the way down to 40 cd/m2 minimum. The control from 400 down to 80 cd/m2 adjusts the intensity of the W-CCFL backlighting unit, and as you adjust the setting it stops at 80 initially. The 'regular' PA271W model actually adjusted the backlight down to a setting of 90, and the 24" PA241W had the same feature but stopped at 130 cd/m2. You can see from the tests above that the contrast remains stable across the whole range from 400 - 80 as you would hope, being recorded at around 1004:1 on average. This was an excellent result and as you would hope from this test and was also significantly better than the PA271W model we had tested back in August. The black point and contrast ratio of that screen then was mediocre really, with an average contrast ratio of 625:1. It seems that NEC have made some improvements to the panel and backlighting unit to allow for a superior black depth / contrast ratio here bringing it in line properly with its advertised spec. Whether there was an issue with the test sample of the PA271W or whether it affects all those models is hard to say without testing further samples, but the PA271W-SV certainly offered a better contrast ratio in our tests.

 

The luminance was recorded at a maximum of 382 cd/m2 which is a fair way over the advertised maximum brightness of the screen of 300 cd/m2 in fact. You probably wouldn't want to use the screen at such a high brightness though as it was very intense and harsh on the eyes. The luminance ranged down to 89 cd/m2 at the lowest backlight intensity which gives you a very good range in which to adjust the screen without sacrificing contrast ratio. The OSD menu figures are actually pretty close to the target luminance as well, being only 10 - 20 cd/m2 out in most cases. You will probably want to adjust the setting to about 110 in the OSD for a comfortable luminance of around 120 cd/m2. Black depth also decreased from 0.38 to 0.09 cd/m2 at the lowest end as these adjustments were made. These results were plotted on the graph below.

 

 

The control of the backlight intensity stops when you reach the OSD setting of 80 cd/m2, and for all intents and purposes you are at a setting of 0% here. However, the PA271W-SV (like the other PA series screens) does allow you to reduce the luminance of the screen even further down to a setting of 40 cd/m2. As you go below the 80 setting, the OSD shows the value in pink, and indicates that you are no longer making backlight adjustments, but you are making digital alterations at the controller board level. This has the effect of lowering the luminance of the screen even more, but since this is a digital white level adjustment only, it does affect contrast of the screen. Black depth cannot go any lower since you are not able to reduce the backlight intensity any more, and so even though white level is changing with the digital alterations, black depth remains at ~0.09 cd/m2. Therefore the contrast ratio drops from ~1004:1 to as low as 489:1 at the lowest luminance reading.

 

Compared with most other monitors you would only normally have access to the backlight intensity control so the PA271W-SV's performance from the 400 - 80 setting is in keeping with other models we have tested. All NEC have done is add an additional digital control should you wish to reduce luminance even further. If you don't want to use this digital adjustment, but need a lower luminance than the 89 cd/m2 we achieved at 80 OSD setting, remember you can achieve lower results through calibration procedures and adjustments at a graphics card LUT level.

 


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 an 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 - ColorComp Off

The above results were recorded using the screen with the 'uniformity' mode disabled. We will look at that technology in a moment. The results of this test were moderate. Luminance did drop down by around -25% in the lower left hand area of the screen, down to a minimum of 96 cd/m2 in the corner area and was a little darker in the bottom left hand region. In the top right hand region the luminance reached up to 130 cd/m2 with a +8% deviation. On the whole though two thirds of the screen area was less than 10% out from the target luminance which was ok. I tested the screen with various coloured backgrounds and saw no colour tinting issues. On a light grey / white background you could just about pick out this uniformity variance if you looked closely.
 

Uniformity Mode - ColorComp

 

   

 

The PA271W-SV manual explains what this function does quite well: "This function electronically compensates for the slight variations in the white uniformity level as well as for deviations in colour that may occur throughout the display area of the screen. These variations are characteristic of LCD panel technology. This function improves the colour and evens out the luminance uniformity of the display. Note that using the 'Uniformity' feature does reduce the overall peak luminance of the display. If greater luminance is desired over the uniform performance of the display, then this option should be turned off. A higher number produces a better effect, but may also reduce contrast ratio."

Uniformity of Luminance - ColorComp Level 5

Uniformity mode is accessible via the advanced OSD menu as shown in the image above. I tested this feature set at level '5' to see whether it worked well or not. I had tested the feature on the PA241W and PA271W as well which had returned excellent results. The outcome was similar with the PA271W-SV. Uniformity was improved nicely across the screen, although we did not have quite as good a starting point as with the other models. Luminance ranged down to 108 (bottom left hand corner) and up to 133 (top right hand corner), but the extremes of the variance were not as bad as before. This technology did a good job and is an excellent feature to include for those who worry about uniformity of images and colour. Unfortunately since the variance in the panel was quite a lot to start with, it still couldn't quite offer a very uniform luminance. Although the panels in the SV are reportedly hand picked, it seems that this does not necessarily guarantee a great uniformity. Results will vary from one model to another as always, but this was still an adequate result.
 

Uniformity - Impact on Contrast

We discussed this a little during our calibration sections, but thought it might be useful to take a few measurements as well. When you enable the ColorComp mode, either via the OSD menu or the SV II software, it does help improve panel uniformity very well. However, it can have an impact on contrast ratio of the screen. I took measurements of luminance, black depth and contrast ratio at each of the 5 ColorComp settings. These were taken while in the High Bright preset mode after software calibration.

ColorComp Setting

Luminance (cd/m2)

Black Point (cd/m2)

Contrast Ratio

Off

119.8

0.14

855:1

1

120.0

0.14

857:1

2

119.9

0.15

799:1

3

119.8

0.16

749:1

4

119.9

0.17

705:1

5

119.6

0.18

664:1

As you can see, the luminance reading of our calibrated profile was rounded to 120 cd/m2 at each setting and the ColorComp does a good job of stabilising this value across the screen. However, black depth was impacted to varying degrees and as a result, contrast ratio ranged from 855:1 when set to off, down to 664:1 at setting 5.



Above: All black screen in a darkened room

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 some slight uniformity differences noticeable in the top right and bottom right hand corners, but these were quite hard to detect with the naked eye to be honest. The camera picked out these differences. Overall there was no serious backlight bleed which was good.

 


Other Tests

I won't repeat the results from our other tests here as you can read our NEC PA271W review for that information. The findings and analysis for the following sections apply to the PA271W-SV as well as nothing has changed between the two models.

 


Conclusion

A lot of what I said about the regular PA271W screen applies here of course, but I will try to concentrate on the differences between that and the SV / Reference version here. Firstly there is a significant price difference between the two models, with the regular edition retailing for around 1050 (inc VAT) and this SpectraView Reference version retailing for around 1600 GBP. There are a couple of tangible differences here of course. Firstly the screen comes with a calibration hood which you do not get with the regular version. Secondly, this model allows for hardware level calibration using NEC's advanced SpectraView Profiler software; something which the regular screen did not allow. If you're going to spend this money on a professional grade screen then you are certainly going to want to calibrate it at a hardware level, and so it's great to see that the SV Profiler now gives that full access. It's a decent piece of software and the provider, BasICColor, are highly regarded in this field.

 

However is this really necessary when you can calibrate either screen at a hardware level using the USA SpectraView II software? That's debateable really as it can happily calibrate the regular and SV versions of the screen. The Profiler software is perhaps a little more advanced and has some nice extra reporting features and testing functions. It also seemed to produce better results from the screen when it was combined with NEC's own wide-gamut i1 Display 2 puck than the SV II software did. However, the SV II software is very easy to use and offers some very impressive results as well. The added functionality of gamut calibration is also very welcome in this latest version and something which the Profiler software cannot offer at the moment. The value of the hardware calibration in Europe is undoubted of course, but when there are very good alternatives with the regular screen anyway, is it really worth that extra money?

 

It's also quite hard to really determine the impact in practice of the reported 'hand picked' and 'tweaked' panels to be honest. We didn't see quite as good a performance in uniformity as we had with the regular PA271W even and factory colour performance was not quite as accurate either. Testing these tweaks in the real World doesn't really show any massive benefit in my opinion.

 

Having said that I was suitably impressed by some of our tests here. The SV II software updates were excellent and very welcome. The NEC branded i1 Display 2 worked very well and at a fraction of the cost of a high end spectrophotometer, would make a good choice if you want to calibrate one of NEC's wide-gamut and PA series screens. There were also some big improvements in black depth and contrast ratio from our tests of the PA271W-SV. I don't know if they have improved this with the regular model as well since our original review, but this could just be a tweak with the SV edition. If it's a 'feature' of the SV edition then that is obviously a big plus for this model as it was an area of weakness in our PA271W review. The fact still remains that this is a very high end screen which offers a wealth of features, options and professional grade performance. I would recommend the SV edition to anyone who has a very high end requirement.

 

 

Pros

Cons

Massive range of calibration potential at a hardware level

High price point due to product positioning

Improved black depth and contrast ratio, now very good

Uniformity not quite as good as hoped (may vary)

Updated SV II software and NEC i1 Display 2 device are very effective

Average input lag (see PA271W review)

 


 

 

 

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