Color-Critical Displays

The color gamut of a display can be calculated in many different ways, and there is no industry standard method. Therefore unless the exact method used to calculate the values is specified it is difficult to compare values between different displays.

NEC calculates the Color Gamut Size and Coverage specifications as a 2D gamut area in CIE 1931 xy or CIE 1976 u'v' colorspace using measurements from a very precise spectrophotometer. The display color gamut is compared to that of a reference gamut, such as sRGB, adobeRGB, or NTSC (1953).

The Gamut Size specification is the total relative display gamut area and includes any colors outside the reference gamut expressed as a percentage. In other words it is the area of the display color gamut triangle vs. the area of the reference color gamut triangle, and does not take into account if the gamuts actually overlap or not – it is just the ratio of the total areas

The Gamut Coverage is the relative display gamut area contained inside the reference gamut expressed as a percentage. In other words it is the area of the intersection of the display color gamut triangle and the area of the reference color gamut triangle vs. the entire area of the reference color gamut triangle. The maximum possible coverage value is 100%.

The official specifications for several SpectraView displays are shown below calculated using both CIE 1931 xy and CIE 1976 u'v' colorspaces:

The MultiSync PA series use a dedicated color processor (SpectraView Engine) that can perform full 3D color gamut transforms to a high color bit-depth internally in the display. This coupled with the individual unit factory measurement and internal stabilization means that very accurate color gamut transforms can be done with no loss in image quality. Compared to many standard color gamut displays, these models are actually capable of proving a more accurate sRGB because they are able to cover 100% of the sRGB color gamut. Many standard color gamut displays do not actually cover 100% of the sRGB color gamut.

The display will automatically identify itself to the host PC as supporting 10 bits when connected via the DisplayPort input. There are no settings that need to be made on the display. You may need to enable 10 bit support in the video drivers on your system. This functionality is currently available for the MultiSync Pa Series displays.

1) A display that supports 10 bit video such as the MultiSync PA series models.
2) A DisplayPort connection between the display and video card.
3) A video card that supports 10 bit video (refer to the manufacturer of your video card to see if it supports 10 bit video on DisplayPort, or see the list below)
4) If necessary, enable 10 bit support in the video graphics drivers.
5) Software that supports 10 bit drawing using either OpenGL or DirectX on Windows.

+

A test/demo application is available for Windows from NEC which will test if 10 bit video is supported and enabled in the video graphics system, and will show a comparison of 8 bit vs 10 bit video.

As of april 2011, there is no support for 10 bit video on DisplayPort with any Mac systems.

adobe has not yet officially publicly announced support (as of april 2011). Some video drivers are available that can force Photoshop to use 10 bits.

You will need to purchase a Mini DisplayPort to DisplayPort cable or "dongle". You can use the Pa-MDP-CaBL from NEC or a cable or dongle from various third party adapters. Be very careful when using a Mini DisplayPort to DisplayPort adapter dongle due to the large mechanical stresses placed on the Mini DisplayPort connector. NEC also offers a Mini DisplayPort to DisplayPort cable.

IMPORTANT NOTE: NEC has identified several 3rd party Mini DisplayPort to DisplayPort cables as being incorrectly manufactured, and which may cause problems. See this document for more details.

Either can be used without loss of quality. Note that only DisplayPort supports 10 bit video.

Yes, but you will not be able to display the full native resolution. These displays require a Dual Link DVI connection in order to support the full resolutions of 2560x1440 and 2560x1600 respectively. A Mini DisplayPort to DisplayPort cable or dongle can also be used to connect to the DisplayPort input.

Yes, the MultiSync PA Series models ship with a cable that can plug into a Thunderbolt port on your Mac and into the DisplayPort port on the monitor. This is the best connection for this configuration.

The CIE 1931 xy colorspace is the more popular and widely recognized colorspace, and engineers are used to using this for calculations and charts. But it does not give equal area representation to different colors—in particular, the size of the green area is overemphasized, but the blue area is underemphasized.

The CIE 1976 u'v' colorspace attempts to correct for this representation problem by scaling the chart so that colors are more equally represented. This means CIE 1976 u'v' is technically more useful for comparison purposes, but not as popular due to legacy usage and recognition.

If you are using a wide color gamut display such as the PA241W, PA271W, PA301W, LCD3090WQXi, or P221W, either the video editing software must be color management aware, or the display monitors should be used in sRGB Emulation mode - otherwise colors will appear to be oversaturated.

No. The NTSC (National Television System Committee) specification for color television encoding was finalized in 1953. Part of this specification defined the color gamut for the system as three color primaries (red, green and blue). The gamut that these primaries actually encompassed was huge and well beyond the limitations of the TV camera and display technology at the time, so it was never actually adopted for TV broadcast applications. a much smaller and more achievable color gamut—known today as SMPTE-C or SMPTE 170M—was officially standardized and adopted by the TV broadcast industry in the 1960s.

The original NTSC 1953 gamut specification has lingered in various charts and tables and has been resurrected in recent years as a large color gamut with which to compare device gamuts, even though it has nothing to do with modern TV applications. It is very important to note that anyone who is doing any kind of video editing or production on their display monitor needs to use a color gamut as close as possible to SMPTE-C or sRGB, and not NTSC 1953. This can be done by either using a display monitor with a color gamut close to sRGB, or by using a wide gamut display monitor together with video editing software that is color management aware, or via the sRGB emulation mode on the display.

Standard gamut displays like the LCD2190UXi, LCD2490WUXi, LCD2490WUXi2 and Pa231W are excellent choices for this type of application because they are standard gamut displays and can be accurately calibrated. sRGB images viewed on these displays will look "normal", even when a non-color managed application is used.

With the introduction of the MultiSync PA series, which include the internal SpectraView Engine, wide color gamut displays, such as the PA241W, PA271W and PA301W, can now emulate any colorspace, thus making them perfectly suited for many different types of applications including web-based work.

These saturation controls normally apply to all colors equally. but with a wide-gamut display, the red and green are typically much more saturated than sRGB, while the blue is typically very close to sRGB.

Because of this, using this control can cause blue to become under-saturated. Using these controls may also interfere with the SpectraView calibration because they may not be able to be reset by applications other than the control panel.

No. The ProPhoto color gamut contains imaginary colors that can not be reproduced.

Use the White Screen Background test pattern available in the Monitor Settings dialog available on the Tools menu to evaluate the screen uniformity. If there are any areas of the screen that appear non-uniform and present a problem with your color workflow and evaluation, try enabling the ColorComp control and adjust the slider control and see if the areas improve. Find the minimum setting that provides the best acceptable improvement. Each display will be different so there is no ideal setting for all displays.

ColorComp will decrease the maximum luminance of the display in order to make the overall luminance and color more uniform. The extent of the luminance decrease will depend on the ColorComp level selected and the individual characteristics of the display.

The ColorComp feature improves the color uniformity of the display by applying a factory measured correction to the display that reduces the luminance of any bright areas on the display screen so the overall luminance and color is uniform. Since it isn't possible to reduce the luminance of pure black on the screen, ColorComp can not improve the uniformity of black.

Ideally you should recalibrate after changing the ColorComp / Digital Uniformity Correction settings.

The A-TW filter is an additional film that is applied to some LCD panels with the aim of improving off-axis viewing of the display by reducing the "glow" effect that can be seen when viewing very dark images at extreme angles on S-IPS LCD panels. While it does reduce the glow effect, it can also introduce a slight coloration artifact that causes the glow to appear green when viewed from one angle, and magenta from another.

The LCD2090UXi, LCD2490WUXi, and LCD2690WUXi use an a-TW polarizer. The LCD2490WUXi2, LCD2690WUXi2, LCD3090WQXi and other models do not.

The recommended and default re-calibration period is every 2 weeks. But some users working in highly critical color applications may calibrate their displays every few days.

The Validate Calibration feature can always be used to verify the display’s white point and Intensity and determine if the monitor needs to be re-calibrated. always remember to allow the monitor sufficient time to warm up and reach optimum color performance before performing any color critical work or calibrating the display.

A brand new display typically needs to be calibrated more often than one that has been in use for several months.

This feature is automatically disabled when you calibrate using SpectraView.

No. While the Digital-to-analog-Converters on the video card may support 10 bits, nothing else in the video chain does, including the Operating System and application software. There is no advantage of using 10-bit analog video, and it will actually have much lower performance than using 8-bit digital.

The Mini DisplayPort to SingleLink DVI adapter will be able to show full native resolution on all displays except the LCD3090WQXi. The Mini DisplayPort to DualLink DVI adapter is required on the LCD3090WQXi in order to display the full 2560x1600 native resolution.

Note: It is currently (as of OS 10.5.7) necessary to use the SingleLink adapter when calibrating the LCD3090WQXi with SpectraView_II. Therefore both adapters are required. See the SpectraView ReadMe file for the SpectraView software for more details.

The profile associated with the Primary display can be easily checked in Photoshop using the following steps:

1. Open the "Color Settings" dialog in Photoshop from the "Edit" menu.
2. Open the "Working Spaces RGB" listbox.
3. Look near the top of the list for an entry starting with "Monitor RGB - ". The text shown after this is the description tag of the ICC profile that Photoshop is current using for the primary display. DO NOT SELECT THIS. Only confirm it is listed and is the same as the profile shown in "ICC Profile" in the "Information Summary" window in SpectraView.

This depends on the source images and what you intend to output them to. Many modern inkjet printers can output colors that are beyond even adobeRGB—especially along the blue-red axis—so a larger working space such as ProPhoto is recommended. It is also recommended to work in 16-bit depth rather than 8 bits when using large working spaces such as ProPhoto.

No. Because your application is color managed it will correctly handle converting your image from sRGB to the monitor's color gamut when displaying an image. You only need to use the sRGB Emulation mode if your are using non-color-managed applications and require images to be displayed in sRGB.

Currently all web browsers that are color managed, such as Safari and Firefox 3, only use the ICC/ColorSync profile for the primary display for color correction. This means that even if a browser window is moved to the secondary display, it is still (incorrectly) using the color correction for the primary display.

Also Safari assumes that all images that do not have an embedded ICC profile are unmanaged and are not color corrected. Only images that have an ICC profile are corrected. Firefox 3 correctly assumes that all images that do not have an embedded ICC profile are in sRGB colorspace.

Internet Explorer does not support color management on Windows.

FireFox 3 supports color management, but it must be manually enabled (see below). all images with no embedded color profile are assumed to be sRGB and are color-managed. Note that only the primary display is correctly color-managed.

Safari is color-managed and enabled by default. Images with no embedded color profile are not color managed. Note that only the primary display is correctly color-managed.

Follow these steps to enable color management:>

1. Type "about:config" in the address bar of Firefox 3.
2. Click thru to the confirmation page and find the following line in the list: "gfx.color_management.enabled".
3. Double click that line so it says "true."
4. Restart Firefox 3.

The information shown in the Color Management tab on the advanced Display Properties in Windows can sometimes get out of sync and incorrectly report which ICC profile is associated with each display.

A more advanced control panel is available from Microsoft for Windows XP which is much more reliable for checking the assigned monitor profile. On the Microsoft website, search for “Color Control Panel applet.”

This can occur when an ICC/ColorSync profile is corrupt or incorrectly installed. Try deleting or regenerating the profile or temporarily assign a different profile to the display.

It depends on the particular application that the monitor is being used for and the software being used. If the software is color management aware, then normally an ICC/ColorSync display profile is needed in order to accurately convert images for viewing. Since the self calibration feature of the LCD3090WQXi and PA301W are entirely self contained within the monitor, they can not generate an ICC/ColorSync profile on your system. also the flexibility of the self calibration feature is limited compared to what can be done with the SpectraView software. So in these cases it is recommended to use the SpectraView calibration software to calibrate and profile the display monitor.

The X-Rite iOne Display V2 is the only sensor supported by the self-calibration feature.

1. When the OSD is not displayed, press the "Reset."
2. In the "Picture Mode" menu, use the left or right buttons to switch between sRGB and Programmable modes.

The Programmable mode is the wide-gamut mode that was calibrated by SpectraView. The Standard mode can be used for any custom settings not relating to sRGB or SpectraView.

It has been discontinued and is no longer available from the supplier.

The following are the main changes made to the LCD2490WUXi2:

1.The color gamut has been modified slightly to more closely match that of sRGB. The sRGB coverage is 96.7% (versus 93.5% on the LCD2490WUXi) in CIE xy.
2. The contrast ratio has been improved from 800:1 to 1000:1.
3. The maximum typical luminance has decreased from 400 to 320 cd/m².