Introduction

NEC are one of the most established manufacturers of professional grade LCD monitors in the market. They have long been producing high quality screens with a wealth of features, advanced technologies and some top end performance to match. Back in 2010 they released their latest PA series of screens which featured models available in 24" (PA241W), 27" (PA271W), 30" (PA301W) and then later, 23" (PA231W). These represented the latest generation of their professional series of screens and brought with them some interesting changes to the range. The 24, 27 and 30" screens all offered a wide colour gamut and "10-bit" colour depth support through the use of the latest generations of so-called Performance-IPS (p-IPS) panels. They maintained some of the advanced technologies which had made the professional range popular over the years including support for hardware calibration of the monitors LUT and inclusion of their own digital uniformity correction called ColorComp. 

The following year in 2011 NEC also released an updated 24" model, designed to run alongside the PA241W. This new P241W model (note the missing "A") was designed to try and bridge the price gap a little between consumer models and the high end screens of the PA series. It featured a standard colour gamut which many users prefer and also reverted to a standard 8-bit panel instead of the 8-bit+FRC ("10-bit") panel used in the PA241W. NEC's 23" model had always followed this route as well, with the PA231W being a standard gamut / 8-bit offering. The newly announced 23" P232W which we have with us for testing is designed to be the successor to the PA231W and again sticks with the standard gamut formula. It uses the latest generation of AH-IPS panel with updated specs and even an improved AG coating. The P series will now therefore be the standard gamut range of professional displays available in 23 and 24", leaving the PA series as the wide gamut offerings in 24, 27 and 30".

NEC's website marketing says: "The 23” NEC MultiSync P232W joins the next generation of MultiSync P Series desktop monitors with key benefits for the areas of web graphics, online video and photography. This model’s widescreen, IPS panel delivers great image performance, and coupled with the built-in USB hub, it allows users to control two computers with only one keyboard and mouse. The ENERGY STAR-qualified P232W offers low power consumption due to its LED backlighting technology and an ambient light sensor, which automatically adjusts the display’s brightness based on lighting conditions. With extensive connectivity, including an HDMI input, and a four-way adjustable stand for ergonomic comfort, the budget-friendly P232W is an exceptional product for tech-savvy consumers and entry-level professional applications."

 

Specifications and Features

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

Manufacturers website link: NEC

The P232W offers a very good range of video connections which is good to see and something you would hope for given the relatively high cost of a pro-grade model like this compared with the mainstream 23" models. There are DVI-D, HDMI, DisplayPort and D-sub provided. The digital interfaces are HDCP certified for encrypted content. The screen comes packaged in the UK with a DVI-D, DisplayPort, D-sub and USB cables. The screen has an integrated power supply so you only need to use the provided kettle lead power cable to power the screen. There is no HDMI cable provided with the screen it should be noted.

There are 3x USB 2.0 ports available, two on the back by the other connections and one on the right hand side for easy access. The screen features a programmable 14-bit 3D LUT and comes with NEC's ColorComp technology for digital uniformity correction. We will talk about these later on in the review in more detail. There is an ambient light sensor featured to allow the screen to automatically adjust the backlight depending on the ambient light conditions of the working environment, and this is referred to by NEC as "AmbiBright". The screen is available in black or white, we have with us the black version.

There are no integrated speakers provided on this model as it is more aimed at professional graphics work than multimedia users. However if you want to you can add the NEC MultiSync Soundbar Pro as pictured above.

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

OSD Menu

 
Above: view of OSD operational buttons. Click for larger version

The OSD menu is controlled through a series of 7 buttons located on the bottom right hand corner of the bezel. In the picture shown above the ambient light sensor is show on the far left, situated next to the power on/off button. The power LED glows blue during normal use, although it can also be changed to green via the advanced section of the menu, along with control over its intensity. In standby the LED glows amber. The next 'input' button gives you quick access to switch between the various video inputs. Pressing 'menu' will of course bring up the main OSD menu which we will look at in a moment.

The left/right arrows give you quick access to control over the brightness setting as shown above.

The PiP button allows you to quickly control the Picture In Picture (PiP) function, while the up/down arrows give you quick access to the picture mode preset menu. When selecting one of these presets the screen also gives you a quick summary of some of the active settings applicable in that mode.

The main OSD menu is split into 7 sections along the top as shown above. The first gives you control over the brightness and contrast (if available) which you would normally find even on the most basic OSD software. There is also access to the ECO mode control which we will test in a moment.

The second section allows you to control a few options related to the picture and its position. There is access to the hardware level aspect ratio control options here as well with options for full, off, aspect and custom available.

The third section gives you control over the preset 'picture mode' along with settings for the white point (colour temperature) and control over the colour channels. At the bottom there is also access to the advanced section of the menu which we'll look at shortly.

The fourth section is the 'tool's menu. You can control the PiP settings here and a couple of other settings including setting an 'off timer' and choosing which USB connection is active if you have connected two PC's to the screen.

The language and OSD settings are available from the 'menu tools' section as shown above.

The next menu gives you some details related to the power consumption of your screen which might be useful in office environments I suppose or to those who really like to keep an eye on how they are helping to save the planet.

The last menu confirms some information about your active settings in an 'information' section.

If we enter the 'advanced menu' section we are presented with a different format to the software, split along the top into 12 sections as shown above. There are loads more options to play with in here if you want, along with access to a few useful features we will want to test.

In the first section you can control the gamma setting if you wish and the ColorComp uniformity correction is located at the bottom there, with settings available from 1 - 5 (and off). In the second tab there is control over the response improve feature, auto brightness and the ambient light sensor.

In section 3 there is only one setting available, section 4 is blank and section 5 only allows some further control over the picture position and aspect ratio control.

Section 6 allows you to control the operation of the USB ports for when you've got more than 1 PC connected to the screen and want to allow connected device to work with either. Section 7 allows you to control the OSD menu settings and also has an option to turn off the NEC boot logo which is handy.

Section 8 has options for PiP and options to allow you to rotate the OSD if you've changed the screen into portrait mode. Section 9 is blank again, and section A has options for the NEC Tile Matrix setup, if you're using more than one screen in a tiled setup.

In section B you are presented with more information about your energy and carbon usage and the last section C gives you information about your screen and settings.

All in all the OSD menu was very easy to use and navigate. The software was fast and intuitive and there was a huge range of options to control.

 

Power Consumption

In terms of power consumption the manufacturers spec states typical usage of 29W. In standby the screen apparently uses 0.3W.

We tested this ourselves and found that out of the box the screen used 24.1W of power while at its default brightness setting which was 70%. At the lowest brightness setting, power consumption was reduced to 14.1W. After calibration at a hardware level the SpectraView II software had achieved the desired 120 cd/m² luminance. The brightness control was not accessible in the OSD menu, but the power consumption was measured at 21.2W in this calibrated state. In standby the screen used 1.9W of power. We have plotted these measurements on the graph below for comparison with other screens.

 

Within the first section of the OSD menu is an option for the 'ECO mode' setting as shown above, designed to give you quick control to preset maximum brightness settings. There are options for off, mode1 and mode 2. Off obviously allows you to manually set the brightness of the display as you wish. Mode 1 allows you to set brightness up to a maximum of 64.3%, while mode 2 caps you at 28.6% maximum. We tested the power consumption at each below

The advanced menu gives you access to NEC's AmbiBright ambient light sensor and auto brightness features as shown above. Through a small sensor on the front of the bezel, the monitor detects your ambient lighting conditions and automatically makes adjustments to the brightness of the display to compensate for changing conditions. This might be a useful feature for some users in variable lighting conditions.

Panel and Backlighting

Panel and Colour Depth

The NEC P232W utilises a LG.Display LM230WF3-SLE1 Advanced High Performance-IPS (AH-IPS) panel which is capable of producing 16.7 million colours with a true 8-bit colour depth. This is the latest generation of so-called AH-IPS panel from LG.Display although in reality it is unclear what really makes these AH-IPS generation panels any different to the older H-IPS (and e-IPS) variants. You may note that the spec on the NEC USA website suggests the screen offers a 1.07 billion colour depth, implying the use of a "10-bit" (or at least 8-bit+FRC) panel. However that site doesn't talk anywhere else about the screen having support for 10-bit colour depth. In fact, that spec is erroneous. The NEC European sites instead list the correct 16.7m spec and we have confirmed with NEC that the model (and indeed the specific panel) is an 8-bit module, with a 16.7 million colour depth.

The screen features a programmable 14-bit 3D Look-Up-Table (LUT) which allows for hardware calibration and a high end control over the device itself. The extended internal processing also helps ensure tonal values and grey scales are maintained as they are processed from the graphics card to the display, from a palette of 4.3 trillion colours. This LUT is 3D and so 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.
 

Panel Coating

The screen coating on the P232W is a normal anti-glare (AG) offering as has been the norm for the rest of NEC's P and PA series screens. Readers will be pleased to hear though that the AG coating is actually nice and light and is not the usual grainy and aggressive solution you would normally find on an IPS panel or on the older models. In fact in practice it is almost what you might call a semi-gloss coating being quite similar to AU Optronics AMVA / Samsung PLS offerings and very comparable to what we saw on the recently released Dell U2713HM. LG.Display seem to have toned down the AG coating which is great news. It retains its anti-glare properties to avoid unwanted reflections, but does not produce an overly grainy or dirty image that some AG coatings can.
 

Backlighting and Colour Gamut

The P232W uses White-LED (W-LED) backlighting producing a colour space approximately equal to the sRGB reference. This means the screen is considered a 'standard gamut' backlight type. Confirmed by NEC in their detailed spec sheet, the colour space is equal to 70.7% of the NTSC space, 75.2% of the Adobe RGB reference and 96.8% of the sRGB space. A wide gamut screen would need to be considered by those wanting to work outside of the sRGB colour space of course. This coverage is actually a little short of the  full sRGB colour space although this probably won't affect many users.
 

PWM Flicker Tests at Various Backlight Brightness Settings

100%                                                50%                                                      10%

We tested the screen to establish the methods used to control backlight dimming. Our recent article talks in more details about a common method used for this which is called Pulse Width Modulation (PWM). A series of photos was taken using the method outlined in the article. These were taken at 100%, 50% and 10% brightness settings. We would normally also test this at 0% brightness but the screen was so dark it was hard to get a decent photograph. These tests allow us to establish 1) whether PWM is being used to control the backlight, 2) the approximate frequency at which this operates, and 3) whether a flicker may be introduced or potentially noticeable at certain settings.

A thin white line was shown on an all-black background and a photograph was taken at a slow shutter speed of 1/8 second (in this example) as the camera was scanned left to right in front of the screen. This produces a series of white lines which can be used to identify the frequency of the PWM and how quickly the backlight is cycled on and off. The higher this frequency, the less likely you are to see artefacts and flicker. The duty cycle (the time for which the backlight is on) is also important and the shorter the duty cycle, the more potential there is that you may see flicker. Please remember that not every user would notice a flicker from the backlight but it is something to be wary of. It is also a hard thing to quantify as it is very subjective when talking about whether a user may or may not experience the side effects. We are able to at least measure the frequency of the backlight using this method and tell you whether the duty cycle is sufficiently short at certain settings that it may introduce a flicker to those sensitive to it.

The NEC P232W showed a cycling frequency of ~176Hz (22 lines at 1/8 second shutter speed) in the initial tests shown here. A further test at an even slower shutter speed confirmed the cycling frequency at approximately 180Hz. At 100% brightness there should be no flicker evident as the backlight is not cycled on and off using PWM. At lower settings PWM is used and the duty cycle becomes progressively shorter. Given the relatively low frequency of the PWM cycling compared with some other displays (e.g. PWM of 350Hz+) and the use of LED backlighting, there is a chance that flicker may be evident to some users as you lower the brightness setting as a result. Some screens we have tested recently (e.g. DGM IPS-27001WPH, Samsung S27B970D and Dell U2713HM) have not used PWM at all, but it it still a long-established technique and obviously still being used widely in the market.

 

Testing Methodology

An important thing to consider for most users is how a screen will perform out of the box and with some basic manual adjustments. Since most users won't have access to hardware colorimeter tools, it is important to understand how the screen is going to perform in terms of colour accuracy for the average user.

I restored my graphics card to default settings and disabled any previously active ICC profiles and gamma corrections. The screen was tested at default factory settings using the DVI interface, and analysed using an X-rite i1 Pro Spectrophotometer (not to be confused with the new i1 Display Pro colorimeter) combined with LaCie's Blue Eye Pro software suite. An NEC branded and customised X-rite i1 Display 2 colorimeter was also used to verify the black point and contrast ratio since the i1 Pro is less reliable at the darker end.

Targets for these tests are as follows:

• CIE Diagram - validates the colour space covered by the monitors backlighting in a 2D view, with the black triangle representing the displays gamut, and other reference colour spaces shown for comparison

• Gamma - we aim for 2.2 which is the default for computer monitors

• Colour temperature / white point - we aim for 6500k which is the temperature of daylight

• Luminance - we aim for 120 cd/m², which is the recommended luminance for LCD monitors in normal lighting conditions

• Black depth - we aim for as low as possible to maximise shadow detail and to offer us the best contrast ratio

• Contrast ratio - we aim for as high as possible. Any dynamic contrast ratio controls are turned off here if present

• dE average / maximum - as low as possible. If DeltaE >3, the color displayed is significantly different from the theoretical one, meaning that the difference will be perceptible to the viewer. If DeltaE <2, LaCie considers the calibration a success; there remains a slight difference, but it is barely undetectable. If DeltaE < 1, the color fidelity is excellent.

 

Default Performance and Setup

It should be noted that the ColorComp uniformity adjustment setting was off by default in the High Bright mode which is how I left it for these tests. When testing the other preset modes I also disabled this feature if it became active by default. This can be controlled via the advanced section of the OSD menu. Other technologies including AmbiBright were also turned off to avoid issues with these tests.

Default settings of the screen were as follows:

NEC P232W - Default Factory Settings, High Bright Mode

   

 

The default set of the screen actually felt very good to the naked eye in the High Bright preset. Colours felt even and not too cold, not too warm. The brightness was a bit high but not blindingly so, and it was set at 70% in the OSD menu. In terms of measurements, the CIE diagram on the left confirms that the monitors colour gamut (black triangle) matches the sRGB colour space (orange triangle) reasonably closely. It extends a little past the sRGB space in some blues and greens, but falls a little short in some reds in this 2D view of gamut. This fits in with the fact we know the spec states a coverage of 96.8% of the sRGB space.

 

 

Default gamma was recorded at 2.2 average, with 0% overall deviance from the target of 2.2 which was great. Note that the screens gamma setting was at "cst 2.2" (custom 2.2) in the OSD menu. The gamma was a little too low in lighter grey tones where it ranged down to 2.17 which is hardly a big difference. A very good default gamma setup from the screen which was good news. White point was also very close to the target, being recorded at 6467k and being only 1% out from the 6500k target while set at the 'native' white point in the menu. Note that we are using a spectrophotometer to make these measurements which is not sensitive to the W-LED backlight as some colorimeter devices can be. When using a standard gamut colorimeter not designed to work with modern backlighting units like W-LED, there can be a typical deviance of 300 - 600k in the white point measurement which is why some sources may refer to a different white point in this test incorrectly.

 

Luminance was recorded at a reasonably high 210 cd/m² which is too bright for continued use in normal lighting conditions really. The black depth was a good 0.21 cd/m², giving us a very good (for an IPS panel) static contrast ratio of 1002:1. This was behind some competing VA matrices of course, but it's still very good for an IPS panel. Colour accuracy was very good overall at default factory settings with an average DeltaE (dE) of 1.7, ranging up to a maximum of 5.6. Along with the very good gamma and white point, this factory setup was very good really. The gamma and white point target in particular were well met. You can of course alter the luminance simply by adjusting the brightness control to achieve a more comfortable setting, without impacting the other areas.

 

NEC P232W - Default Factory Settings, sRGB mode

   

 

We also carried out tests to establish the default setup in some of the other preset modes. First we tested the sRGB preset mode. When switching to this mode you could immediately notice a big drop in the luminance of the display. Looking at the OSD menu confirms the brightness control was now reduced to a default of 21.4% (down from the 70% setting in the High Bright mode). White point had now been set at 6500k in the OSD menu and the gamma was set at 'sRGB'.

 

You may notice from the CIE diagram that the colour space coverage has changed ever so slightly compared with the default High Bright state. It seems that the screen is trying to emulate a slightly smaller colour space and more closely match the sRGB reference. Given the pretty close native match anyway, we're not sure this is of much real benefit. It's not like on a wide gamut screen where it can be very useful to emulate a smaller colour space where needed.

 

Gamma on average was still 2.2 with a 1% deviance, but studying the more detailed gamma information in the table above shows that the gamma curve was not correct, being too low in darker greys (down to 2.07) and too high in light greys (up to 2.25). The white point was still accurate with only 1% deviance at 6556k. The luminance of the screen was recorded at a much lower 79 cd/m², but the screen retained its high contrast ratio at 998:1. Colour accuracy was not quite as good as before, with dE average of 2.0 and a maximum of 9.6 where blue shades were not correct.

 

 

NEC P232W - Default Factory Settings, Full mode

   

 

We also tested the screen in the 'Full' preset mode. The default brightness in this preset was 50% and so gave us a pretty comfortable 158 cd/m² luminance measurements, with the 998:1 contrast ratio still being retained thankfully. The colour space was reflective of the backlights native gamut here as we had seen in the High Bright mode as well.

 

 

Gamma and white point were very accurate again which was excellent. Colour accuracy was also very good in this preset with dE average 2.0 and maximum was 5.4. This is just as good a default preset as the high bright mode really, just with a lower and more comfortable luminance.

 

 

Testing Colour Temperatures

 

 

The P232W features a good control over the colour temperature (white point) setting from within the 'RGB' section of the OSD menu as shown above. We measured the screen with the X-rite i1 Pro spectrophotometer in a sample of the settings to establish their colour temperature / white point. The control actually allowed you to adjust the white point in 100k steps, although we have included results below at 500k or 1000k intervals. All other settings were left at factory defaults and we left the screen in the High Bright preset mode. There was no ICC profile active either. The results are recorded below along with the deviance from the target setting.

 

 

 

As you can see, the colour temperature settings from 3000 to 9000k were all very close to the target white point, and within 100k of where they should be. This represented a deviance of <1.5% in all cases which was very good. As the colour temperature setting got cooler there was a bigger deviance introduced. From 9500k to 15,000k (the maximum setting) the deviance grew, with a max difference of 410k. In fact although there was a bigger deviance from the target setting the % difference was still very small and <3% overall, even in the worst cases. The colour temperature settings seemed to be very close to their targets overall, particularly in the warmer part of the range which was good news.

 

 

 

Software Calibration Results

 

The NEC P232W may well have a decent factory setup but given the market for this screen I expect many users will want to calibrate the screen personally to obtain even higher levels of accuracy and allow profiling and matching between different devices.  Remember, you need to ensure you have a device capable of measuring and reading the spectra from the W-LED backlight unit properly. Many older colorimeter devices are designed to work with standard gamut CCFL units only and so they can often have difficulty reading LED (and wide gamut CCFL) units properly. A spectrophotometer does not have this problem and there are also some decent modern colorimeters like the X-rite i1 Display Pro which can read W-LED without issue. While you can use other devices and various software packages to complete software profiling of the screen, you may come across issues if the device is not designed to work with a W-LED backlight unit.

 

The P232W also offers a hardware calibration engine which can give you very high levels of accuracy and control over the hardware 14-bit 3D LUT itself. We will test that in a moment, but we also wanted to carry out the usual software level "calibrations" (profiling) at a graphics card level. We used the X-rite i1 Pro spectrophotometer combined with the LaCie Blue Eye Pro software package to achieve these results and reports. An NEC branded and customised X-rite i1 Display 2 was used to validate the black depth and contrast ratios due to lower end limitations of the i1 Pro device.

NEC P232W - Software Calibrated Settings, High Bright Mode

Monitor OSD Option	Calibrated Settings
Brightness	39.3
Contrast	n/a
Picture mode	High Bright
White	Native
Gamma	Cst 2.2
Metamerism	Off
ColorComp	Off

	Calibrated Settings, High Bright mode
luminance (cd/m2)	120
Black Point (cd/m2)	0.13
Contrast Ratio	940:1

 

I first of all profiled the screen in the default High Bright mode. Adjustments were made to the screen via the OSD menu as shown above, with the only real change being the reduction in the brightness control. The profilation was a great success. Gamma, white point and luminance targets were all met very well, with 0% deviance from each in our measurements. Colour accuracy was now improved as well, correcting the default 1.7 dE average and producing a dE of 0.3 average, 1.1 maximum. LaCie would classify colour fidelity as excellent now. The calibrated contrast ratio was excellent for an IPS panel at 940:1.

 

 

Testing the screen with various colour gradients showed very smooth transitions. There was hardly any gradation and no noticeable banding was introduced due to the adjustments to the graphics card LUT from the profilation of the screen. It's worth also commenting on the screen coating in this section of the review. Unlike many other IPS panels, including the older PA series screens and the PA231W predecessor, this screen does not feature the usual heavy and aggressive Anti-glare (AG) coating which can sometimes lead to grainy and dirty looking images. Instead it uses a light AG screen coating and as a result the colours look more clean and crisp, the image quality is sharp and whites in particular look more pure than they do on heavy AG coated screens. It isn't a full glossy solution which adds another level of clarity and changes the overall feel of the screen, but it is an improvement over the heavy AG coating of some other IPS screens, including the previous NEC P and PA series models. A positive change and hopefully something we will start to see more of with future IPS screens.

 

You can use our settings and try our calibrated ICC profile if you wish, which are available in our ICC profile database. Keep in mind that results will vary from one screen to another and from one computer / graphics card to another.

 

NEC P232W - Software Calibrated Settings, sRGB Mode

   

 

We also carried out a software profiling in the sRGB preset mode. Results were again very pleasing, with targets being met very well. Contrast ratio was maintained at a very good 935:1 and colour accuracy had been improved nicely from the default of 2.0 dE average to 0.4. Again you can use our settings and try our calibrated ICC profile if you wish, which are available in our ICC profile database. Keep in mind that results will vary from one screen to another and from one computer / graphics card to another.

 

 

 

Hardware Calibration

 

To take full advantage of the screen for calibration 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 (and lower cost) 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:

1) SpectraView Profiler - A European piece of software provided by BasICColor. High end software with a lot of features including a nice validation function. In Europe, this is the software which NEC recommend with their PA / P series. However, to take full advantage of the hardware calibration you must have the specific SpectraView (SV) or 'Reference' version of the screen. The regular P model (like the one we have with us here) will only allow software level calibration using this software. This is due to a firmware lock active on the screen which means the Profiler software cannot communicate with the hardware LUT and so cannot fully hardware calibrate the screen. You cannot calibrate the monitors internal LUT unless you have the SV / Reference edition of the screen which is a higher cost. NEC tell us that in Europe the SV edition of the screen will be available in the near future.

 

2) SpectraView II - A piece of software provided by NEC in the USA instead of the Profiler software. It's less complicated and not quite as in depth but fully automated and easy to use. This will allow you to calibrate both the standard and SV versions of the screen, whichever country you are in, at a hardware LUT level which is good. This software will allow us to calibrate the P232W at a hardware LUT level even in the UK.

 

There are other factors which come into play when talking about the SV version of the screen and the Euro and US versions of the SpectraView software. Please see the full detail in our PA271W review for further information.

 

It should be noted also that other third party software packages such as LaCie Blue Eye Pro, and Quato iColor Display will only support software level calibration on the P232W screen. The SpectraView / Reference edition of the P232W will be available in Europe in the near future.

 

 

SpectraView Profiler

 

We won't go into a massive amount of detail about the software again here as we've already looked at it in detail in our SpectraView Reference 271 review. SpectraView Profiler is currently up to version 5.0.3 and NEC provide a free 14-day trial licence even via their website.

 

 

You will see when loading the software up on the European P232W model (regular, not SV edition) that the hardware calibration option is greyed out. Even the 'combined hard- and software calibration' method is not available, which was actually possible on some of the other P series screens. That would allow automated control over a few basic adjustments like the brightness control, but not a full LUT adjustment. All we can do here is a software calibration like we had previously completed with the LaCie software. We will do so for completeness.

 

We left the screen in the High Bright preset mode for this software calibration. Within the SpectraView Profiler software we defined all our usual review targets. We then used the luminance measurement feature in the software to establish the correct brightness setting for the monitor to achieve our target 120 cd/m² luminance before starting the automated process and the profiling of the screen.

 

NEC P232W - Software Calibrated Settings, High Bright Mode
SpectraView Profiler

   

 

As you can see the reporting feature is quite detailed in this software and provides a good alterative to packages like the LaCie Blue Eye Pro suite. The software itself is provided by BasICColor so it is overall the same as their software, just re-branded as NEC's SpectraView Profiler. We have provided the validation reports above after the software calibration which confirms the success of the profiling and resulting setup.

 

The profiling was a great success and targets were met very nicely as you can see above. This provides a good calibration option for those wanting to software profile the screen. You must of course have a suitable calibration tool to do so. Again you can use our settings and try our SpectraView Profiler calibrated ICC profile if you wish, which are available in our ICC profile database. Keep in mind that results will vary from one screen to another and from one computer / graphics card to another.

 

 

SpectraView II

 

 

We now wanted to carry out a calibration using the SV II software which would allow us to hardware calibrate the monitors 14-bit 3D LUT, even on the 'regular' P232W model in Europe. The latest SV II software is v 1.1.12.1 as shown above and you will see they have added support for the P232W screen. Again, we won't go into a massive amount of detail about the software here as we've already looked at it in detail in our SpectraView Reference 271 review.

 

 

The calibration targets were defined as normal in the software package and the process is entirely automated from there. Note that you need to change the ColorComp uniformity correction level within the SV II software to your liking. If you calibrate with this enabled it will impact the resulting contrast ratio and likely other areas of the setup. For now, we disabled this feature using the 'monitor settings' section of the software shown above. The screen enters automatically into the 'programmable' preset mode where many options in the main OSD are then greyed out. At the end of the process this preset mode is actually then named 'SpectraView II' in the menu.

 

 

The results from the calibration are presented after the process is completed as shown above. The software lacks some of the more advanced reporting features found in the SpectraView Profiler software but does at least give you some decent feedback on the results. Targets had been met nicely here. You may note we have removed the black depth and contrast ratio measurements from this report as again the i1 Pro device was being used and is unreliable at the low end. We will validate the black depth and resulting contrast ratio in a moment independently.

 

 

The second tab confirms the gamut coverage, which here seems to extend beyond the sRGB space in green shades and has some under-coverage in blues. We had initially calibrated the screen with the colour space left on 'native' in the SV II software.

 

 

The curves tab confirms the gamma curve created.

 

 

The colour tracking tab confirms average dE of 0.28, maximum of 0.85 in their report.

 

NEC P232W - Hardware Calibrated Settings, Full native gamut
SpectraView II

   

 

We also used LaCie's test and report feature afterwards to validate the output. The results were very positive with targets for gamma, white point and luminance all being met well. Using an X-rite i1 Display 2 device we checked the black depth and measured a calibrated static contrast ratio of 939:1 which was very good for an IPS panel. Colour accuracy was very good with average dE of 0.4 and maximum of 1.7. Gradients were very smooth with no noticeable banding and only slight gradation in darker tones.

 

 

We also wanted to test the screen using the specific sRGB emulation option within the SV II software. We defined our normal targets but changed the desired colour space to sRGB to see if the monitor could accurately emulate that reference.

 

 

The calibration results are shown here again with the sRGB gamut selected.

 

 

As you can see, the colour space now exactly matches the sRGB reference as measured in the SV II software. The emulation seemed to work very well.

 

 

The resulting colour accuracy was measured with an average of 0.49 dE and maximum of 1.28 in SV II.

 

NEC P232W - Hardware Calibrated Settings, sRGB gamut
SpectraView II

   

 

We carried out the test feature in LaCie Blue Eye Pro again. This time although the colour space coverage had changed and now looked like the sRGB emulation mode we'd tested from the preset menu, some of the other results were not as good. There was some slight discrepancy in the gamma, white point and luminance here. More noticeable was the colour accuracy where average dE was now 1.2 and maximum was 5.2. We tried several attempts to correct this but it seems the screen did not offer the same levels of accuracy when calibrated to the defined sRGB colour space. Given the screens native gamut is very close to sRGB anyway this might not even be needed by many users and they can just hardware calibrate at native gamut.

 

 

 

Calibration Performance Comparisons

 

 

I've provided a comparison above of the P232W against some of the other screens we have tested. There are a lot of different calibration results achieved in the previous sections, both through software profiling in different preset modes, and through hardware calibration. For reference I have taken the hardware calibration results using SpectraView II and the native monitor gamut for the comparisons here.

 

Out of the box average dE was 1.7 which was very good really and combined with the excellent default gamma and white point represented a good factory calibration. It offered a similar level of accuracy to the NEC PA231W before it in terms of colour accuracy (dE average 1.6) but this replacement model has a better gamma and white point setup out of the box which is good news.

 

 

Once calibrated the dE average was reduced to 0.4. This would be classified as excellent colour fidelity by LaCie. It was not quite as low as some of the other screens here which reached down to 0.2 average, but in practice you would not notice any difference here at all. The professional range models from NEC and Eizo like this P232W are even more accurate than other models shown here. Professional grade monitors like this offer other high end features which separate them from some of these other models, including extended internal processing, 3D LUT's and hardware calibration. These comparisons are based on a small selection of tests, so it should be remembered that other factors do come into play when you start talking about professional use.

 

 

The calibrated black depth and contrast ratio of the P232W was excellent really for an IPS panel. The calibrated static contrast ratio was 939:1 which was about as good as you can hope for from an IPS matrix at the moment. Other panel technologies like AMVA and PVA can reach higher, with static contrast ratios >3000:1. Given the use of an IPS panel here, the contrast ratio was very pleasing.

 

 

Contrast Stability and Brightness

 

The luminance range of the screen was very good. At the top end the panel reached 291.23 cd/m² which was even higher than the specified maximum of 250 cd/m². At the lower adjustment end it could reach down to a very low 25.59 cd/m² meaning the screen should be perfectly fine even in darkened room conditions, and for those who like to run at a lower luminance setting. A brightness setting of ~35% should return you a default luminance of around 120 cd/m² as well. Black point remained low across the adjustment range, from 0.29 cd/m² down to 0.02 cd/m².

We have plotted the luminance trend on the graph above. The screen behaves as it should, with a reduction in the backlight intensity controlled by the reduction in the OSD brightness setting. This was pretty much a linear relationship although the top end of the adjustment settings had a slightly lower impact on the resulting luminance.

Contrast was mostly stable across the range, but there did seem to be some slight instability at the lower adjustment end. On average the static contrast ratio was measured at 1006:1.

 

Viewing Angles

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

Viewing angles of the NEC P232W are very good and as you would probably expect from an IPS panel. Horizontally the fields of view were very wide and a gamma shift was only really introduced from a wide angle. Vertically the gamma shift was a little more pronounced but overall the fields of view were very good. The panel was free from the off-centre contrast shift you would see from VA matrices and this is one of the reasons why IPS is so widely regarded as the panel technology of choice for colour critical displays. The panel of course offered far wider viewing angles than TN Film matrices which can be very restrictive, especially vertically.

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

On a black image, like many other IPS panels, there is a white glow when viewed from an angle. This picture was taken in a darkened room though and in normal working conditions this shouldn't present much problem. There is no A-TW polarizer or equivalent film on this panel which was something rarely used in the IPS market, but was implemented on some older IPS screens to improve the off centre black viewing. In practice because the screen is relatively small at 23", you shouldn't notice many issues with this 'IPS-glow'.

Panel Uniformity

Measurements of the screens luminance were taken at 35 points across the panel on a pure white background. The measurements were taken using BasICColor's calibration software package, combined with the NEC customised X-rite i1 Display 2 colorimeter. The above uniformity diagram shows the difference, as a percentage, between the luminance recorded at each point on the screen, as compared with the reference point of a calibrated 120 cd/m². This is the desired level of luminance for an LCD screen in normal lighting conditions, and  the below shows the variance in the luminance across the screen compared with this point. It is worth noting that panel uniformity can vary from one screen to another, and can depend on manufacturing lines, screen transport and other local factors. This is only a guide of the uniformity of the sample screen we have for review.

Uniformity of Luminance (ColorComp Off)

We tested the screen initially with the ColorComp uniformity correction feature disabled. We will look at that in a moment. Without this correction on, the luminance uniformity of the P232W was still pretty good overall. There was some slight variance in luminance, mostly along the bottom and left hand edges where it dropped down to 103 cd/m² in the worst cases (-16.5% deviance). The left hand edge was a little darker than the middle section of the screen, dropping down to around 108 cd/m². 80% of the screen was within 10% deviance of the target / centre of the screen.

ColorComp Uniformity Correction

The ColorComp uniformity correction is available within the advanced picture menu as shown above, at the bottom of sub-section 1. This feature can be turned off, or controlled from levels 1 to 5, with 5 being the highest level. This is designed to stabilise luminance across the screen to produce a more uniform picture. The only downside is that it impacts contrast ratio at the same time.

 

Uniformity of Luminance (ColorComp Level 5)

 

We took our same measurements of the luminance again across the screen with uniformity correction on level 5 and the results were very impressive. Any variance we had seen before had been almost completely eliminated. The maximum deviance from the target at any point was only 2.4% and 100% of the screen was within 2.5% deviance from the target. This technology worked very well which was great news. By enabling this function it does reduce the contrast ratio a bit although even at level 5 we measured a static contrast ratio of 856:1 which was still very good (compared with ~1006:1 in High Bright by default with the setting off).

 

Backlight Leakage

Above: All black screen in a darkened room. Click for larger version

As usual we also tested the screen with an all black image and in a darkened room. A camera was used to capture the result. There was no major backlight leakage although there was some clouding in the right hand corners which the camera picked up in the photo above. This shouldn't present any major problem in practice though and it was quite minimal.

General and Office Applications

The P232W is obviously aimed primarily at the professional market, so it's sensible to assume office applications could well form part of that day to day work. The 1920 x 1080 resolution and 23" screen size give a nice decent area in which to work although the vertical resolution is a little less than 16:10 aspect 24" models (1920 x 1200). I think you notice this if you come from a 16:10 format screen. Also consider the fact that high resolution 27" 2560 x 1440 models are becoming increasingly available. The difference in desktop size is certainly noticeable coming from a 27" screen like that. Nevertheless, the 23" 1920 x 1080 resolution should be adequate for many users. The screen offered a comfortable 0.265mm pixel pitch which delivered easy to read text at a nice size, in my opinion. The resolution is certainly big enough for side by side split screen working as well in many cases.

 

We should mention the AG coating again here. This latest generation of AH-IPS panel features a light AG coating which is much less aggressive than older AG coatings used on many other IPS screens, including the previous PA and P series models from NEC. This means that the screen does not suffer from the same grainy and dirty appearance, which can be particularly apparent on white office backgrounds. It's nice to see a more subtle AG coating here, as we'd also seen on the Dell U2713HM recently.

 

Default luminance of the screen is a little too high at around 210 cd/m² at the default 70% brightness setting. You will probably want to turn this down to around 35% for a comfortable luminance around 120 cd/m². Those wanting to use the screen in low lighting conditions shouldn't have any issue here as the brightness control offers an excellent adjustment range, down to ~26 cd/m² in fact. The default colour, white point and gamma setup are very good thankfully so even without a colorimeter device you should be able to achieve decent performance from the screen easily.  There's no specific preset mode for 'text' or 'internet' so you will need to either calibrate one of the existing modes to a comfortable level, or perhaps set one of the programmable preset modes up how you like. The screen's auto-brightness (AmbiBright) control is useful I think for office work, allowing you to automatically control the brightness of the screen with changing ambient lighting conditions.

 

I tested the screen with both DVI and D-sub interfaces, and the DVI signal was a little sharper than VGA. You will want to use DVI for the sharpest text and image. The USB ports are handy for connecting external devices, although it would have maybe been handy to see more than 1 on the side of the screen for easy access. A card reader is featured on some other models, but not here. There is at least a very good range of ergonomic adjustments for obtaining the optimum viewing position as well.

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

The screen is designed to run at its native resolution of 1920 x 1080 and at 60Hz refresh rate. If you want to you can run it outside of this and let the image be scaled to fill the screen. At the native resolution text was very sharp and clear. We ran the screen at 1600 x 900 which was the next step down, while still maintaining the screens 16:9 aspect ratio. Text was actually good and was not blurred too much, although of course you do take a hit in terms of resolution. To give you more desktop real estate and maximum picture quality, the native resolution is of course recommended where possible.

 

Responsiveness and Gaming

The P232W is rated by NEC as having an 8ms G2G response time which implies the use of overdrive / response time compensation (RTC) technology. This is used to boost pixel transitions across grey to grey changes and improve responsiveness in practice, and reduce ghosting and blurring. The panel being used is an LG.Display LM230WF3-SLE1 AH-IPS Panel and it is rated with a 14ms ISO response time for reference.

Before we get in to the side by side screen comparisons I want to quickly talk about the 'response improve' (overdrive) control available through the screens OSD menu. It is available within the advanced menu, sub-section 2 as shown above. This allows you to manually control the level of overdrive / RTC impulse being applied to the pixels, with options for on and off being available. You may wish to read our specs section for some further information about overdrive / response time compensation.

The screen was tested using the chase test in PixPerAn, a good bit of software for trying to quantify differences in real terms responsiveness between monitors. As a reminder, a series of pictures are taken on the highest shutter speed and compared. The images above are the best case examples from the screen with the 'response improve' setting off and then on. With response improve turned off the overdrive impulse should be turned off in theory although even without it on, the screen performed reasonably well. There was no major ghosting and only moderate motion blur from the moving car. The performance wasn't too bad really.

When switching the response improve setting to 'on' you could detect a slight improvement with the naked eye. The blurring was reduced a little and thankfully no obvious overdrive overshoot was introduced. Sometimes where overdrive impulses are very aggressive or poorly controlled this can lead to dark or pale trails behind the moving objects where the pixels "overshoot" their required state. In the case of the P232W there was none of this evident and the screen performed well. Overall this was impressive considering it's not a screen aimed at gaming really at all.
 

Display Comparisons

The screen was tested again using the chase test in PixPerAn for the display comparisons. As a reminder, a series of pictures are taken on the highest shutter speed and compared, with the best case example shown on the left, and worst case example on the right. This should only be used as a rough guide to comparative responsiveness but is handy for a direct comparison of the impact of this setting:

23" 8ms G2G LG.Display AH-IPS (response improve = on)

23" 8ms G2G LG.Display e-IPS (response improve = on)

24" 8ms G2G LG.Display p-IPS (response improve = on)

I have provided first of all a comparison of the P232W against its predecessor, the PA231W and NEC's 24" PA241W model. As you can see, in all three cases the response improve feature was enabled as this has shown to offer improved responsiveness on the NEC P series without any obvious overshoot issues being introduced. The P232W showed very similar performance to the PA231W model in these tests, both of which seemed to be a little faster than the 24" model.

23" 8ms G2G LG.Display AH-IPS (response improve = on)

23" 14ms ISO LG.Display e-IPS

23" 8ms G2G LG.Display e-IPS

Comparing the P232W then against two other 23" models shows some more significant differences. In the case of NEC's own EA232WMi model, they did not offer any overdrive feature at all and the panel was quite slow as a result. It shows more noticeable motion blur in practice which is picked out in these tests. The Dell U2312HM had offered us some low levels of motion blur thanks to its quite aggressive overdrive impulse. However some noticeable dark artefacts were sadly introduced as a result which you can see in the above images.

23" 8ms G2G LG.Display AH-IPS (response improve = on)

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

24" 8ms G2G LG.Display e-IPS

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

Above is a comparison of the P232W against some popular 24" sized models. The HP ZR2440w had performed well in these tests and showed a similar level of motion blur to the P232W in practice. There was a very slight dark and pale halo trail evident in those tests but it was very slight. The Dell U2412M again offered low levels of motion blur but a more obvious dark overshoot trail was introduced, as we'd seen on the 23" U2312HM as well. I have also included the results from the BenQ GW2450HM since there had been some big improvements made in AMVA panel technology in this most recent generation of panel. Thankfully the responsiveness was much better than we'd seen from older AMVA panels. The NEC P232W actually performed very favourably in these comparisons which was good.

23" 8ms G2G LG.Display AH-IPS (response improve = on)

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

27" 1ms G2G Chi Mei Innolux TN Film + 120Hz (Over Drive = 0)

22" 3ms G2G Samsung TN Film + 120Hz

I've also included a comparison above against three very fast 120Hz compatible screens we have tested. In all cases these other screens are using TN Film panels and are aimed primarily at gamers. Firstly there is a comparison against the BenQ XL2420T. This showed very low levels of motion blur, but some dark overshoot was introduced as a side-effect. The Iiyama G2773HS was very responsive and even has a quoted 1ms G2G response time. This showed very low levels of blur and had minimal issue with overshoot. The Samsung SM2233RZ performed very well in these tests and showed very low levels of motion blur also. When 120Hz mode was enabled the overdrive artefacts evident in 60Hz mode were almost completely eliminated, which is something we have seen with the BenQ XL2420T as well.

While these pixel response tests show the P232W to have fast transitions and low levels of motion blur, there is something else going on here though as well which can't be picked out by the camera. All of these other TN Film models are running at 120Hz refresh rates, which allows for improved 120fps frame rates and the support of 3D stereoscopic content as well. This can really help improve smoothness and the overall gaming experience so these screens still have the edge when it comes to fast gaming. From a pixel response point of view the P232W performed very well, but there are some other areas you still need to think about when it comes to high end gaming. It couldn't keep up with the very fast TN Film models with 120Hz support.

The responsiveness of the P232W was pleasing, especially considering the screen isn't aimed at gaming at all. It offered low levels of motion blur and freedom from any obvious ghosting. The response improve feature helped a bit and should be enabled where possible for optimum performance. The screen also showed no signs of overshoot from the overdrive impulse which was positive news. For those who might like to game sometimes on this screen, the P232W should be able to handle that fine.

Additional Gaming Features

 

Aspect Ratio Control - The screen offers several options within the OSD menu for hardware level aspect ratio control. They are available in the 'expansion' option as shown above with options for full, aspect, off and custom.

Preset Modes - There is no specific game preset available from the screen so you will have to set up one of the other modes to your liking. This is probably only because its not really a screen aimed at gamers.

 

Input Lag

It is important to understand fully what input lag is and also the various measurement techniques which are used to evaluate this aspect of a display in the industry. As a result of our studies, we have improved our testing methodology by adopting the SMTT 2.0 tool which is used to generate the results below. Please see our full input lag testing article for all the details.

Input Lag Classification

To help in this section we will also introduce a broader classification system for these results to help categorise each screen as one of the following levels:

• Class 1) Less than 16ms / 1 frame lag - should be fine for gamers, even at high levels

• Class 2) A lag of 16 - 32ms / One to two frames - moderate lag but should be fine for many gamers. Caution advised for serious gaming and FPS

• Class 3) A lag of more than 32ms / more than 2 frames - Some noticeable lag in daily usage, not suitable for high end gaming

For the full reviews of the models compared here and the dates they were written (and when screens were approximately released to the market), please see our full reviews index.

Our tests here are based on the new format using SMTT 2.0. We have provided a comparison above against other models we have tested to give an indication between screens. We have only included screens which were tested using this new method to allow for a fair and realistic comparison, and have removed any models tested using the old method.

The NEC P232W shows a moderate level of input lag, just over 1 frame in delay. This was measured at 20.9ms average. The lag of this screen has been categorised as CLASS 2 as detailed above. As such it may not be quite as suitable as other models for very high end gaming or fast first person shooters, but then again, this isn't really a gamer-orientated screen anyway.

 

Movies and Video

 The following summarises the screens performance in video applications:

• 23" screen size makes it a pretty small option for an all-in-one multimedia screen nowadays, being quite a bit smaller than modern LCD TV's and many other desktop monitors now available.

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

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

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

• Good to see HDMI and DisplayPort provided along side DVI as it's very useful for external Blu-ray / DVD player connectivity. Might have also been good to see an HDMI cable provided in the box, but we can understand why it's been left out from a cost perspective. DisplayPort is at least included

• Wide brightness range adjustment possible from the display, including good maximum luminance of ~291 cd/m² and very good minimum luminance of ~26 cd/m². Should afford you very good control for different lighting conditions.

• Black depth and contrast ratio are very good for an IPS panel. Shadow detail in darker scenes should not be lost.

• Dynamic contrast ratio not available on this model, in case there's those who like the feature.

• No specific 'Movie' preset mode available so you would have to set up one of your other modes if you wanted tweaked appearance for movie viewing.

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

• Good hardware level aspect ratio control options which may be useful for connection of external devices, DVD players etc.

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

• Very good range of ergonomic adjustments available from the stand meaning it should be possible to obtain a comfortable position for viewing, even with several viewers.

• No significantly noticeable backlight leakage, and none from the edges which is good. This type of leakage may prove an issue when watching movies where black borders are present but it is not a problem here.

• No integrated stereo speakers on this model but you can add NEC's Soundbar if you wanted to.

• Picture in picture (PiP) is available on this model in case you need it, but picture by picture (PbP) mode is not

• For PAL sources, we have tested the screen and confirmed it will support the full native resolution of 1920 x 1080 at 50Hz refresh rate.

 

Conclusion

The NEC P232W proved another solid addition to the P series of screens. As a replacement to the PA231W model there was a move to W-LED backlighting which brought with it energy and environmental benefits. NEC have also swapped one DVI port for HDMI which we think is a useful move. The standard gamut was retained from the older model and the advanced features like hardware calibration and uniformity correction were included again. The latest generation of IPS panel brought with it some positive changes too, most notably with the lighter AG coating.

While many of the features of the older screen remained, some aspects of the performance were improved which was positive news. The default setup was better, with a more accurate gamma and white point. There was a higher adjustment possible from the backlight in case you needed to operate the screen in brighter conditions and the native uniformity of the screen seemed better as well. The hardware calibration worked very well as it had done on the other NEC P models we have tested, and ColorComp worked excellently to improve luminance uniformity. There was also minimal backlight leakage on the P232W which had been a problem when we'd tested the PA231W before. We were very pleased with the performance overall of this screen, with it even offering a decent pixel responsiveness which you might not even expect from a professional grade screen.

Of course the price point is quite high compared with other mainstream 23" models. With a retail price of ~£420 GBP (inc VAT) in the UK it is considerably more expensive than popular IPS models like the Dell U2312HM (~£190) or Asus PA238Q (~£210) for instance. However, it offers some high end professional features which explains the additional cost. If you want a professional grade screen for colour critical work and want a smaller sized screen, this is an excellent option.