Post-photographic equipment (2): How to use wide color gamut display correctly

How is a series of digital photography post-processing tutorials, focusing on PS technology. This chapter mainly introduces how to correctly use one of the most important tools in the later stage of photography: wide color gamut display.

This paper is mainly based on the problems that friends who have bought wide color gamut monitors may encounter in use, and answers them. Movie friends who don't know how to choose a monitor can read the article "What kind of monitor does a photographer need". In this article, I carefully introduce how to choose a monitor.

Many people will ask, do I really need a wide color gamut display when most terminals are almost sRGB devices? If you are a photographer who has requirements for image quality, the answer is that you need a monitor with a wide color gamut. And suggest that you'd better buy a professional camera monitor. Because:

A: SRGB can't cover CYMK. If pictures need to be printed, there must be a wide color gamut display.

B: In the process of processing RAW format photos, the wide color gamut display gives you a chance to see more color details.

C: Usually, the real wide color gamut displays are high-level professional displays, and the technical indicators such as color accuracy, dynamics and color depth of these displays are relatively good.

D: Wide color gamut is becoming more and more popular, which is bound to be a trend in the future.

For example, the SW270C of BenQ in my hand has a screen size of 27 inches and a resolution of 2560x 1440. The size is just right and the resolution is fine enough. In terms of color gamut support, 100%sRGB, 99% Adobe RGB and 97% P3 color spaces are also provided to meet the needs of professional photographers, and there is no problem in the later use of photography. In terms of color temperature, whether in sRGB or Adobe RGB mode, the color temperature of SW270C hardly deviates from the standard color temperature of 6500K K K. ..

Although the wide color gamut display can bring a lot of convenience to photographers, there are still some problems in the use process. Note that the system can correctly load the color description file of the monitor whether it is mac or win. Generally speaking, no additional settings are required:

At the same time, this color description file basically matches the optimal color gamut of the display, and BenQ SW270C corresponds to Adobe RGB, so it is necessary to switch the display to Adobe RGB color gamut. As shown in the figure below:

Next, let me explain the most important knowledge points of this article. After understanding this knowledge point, the content behind this article is actually very easy to understand. In fact, the color that the monitor can display is certain, unless you manually adjust the RGB gain of the monitor. The function of the display color profile is to tell the system how to map colors to the color space of the display itself. However, the desktop, interface and desktop background of Windows system will not be converted by using the monitor configuration file. Therefore, if you manually switch the color profile of the monitor in Windows, the system color will not change. This is the main reason for the color difference in wide color gamut mode of windosw system. On the contrary, the desktop interface of the Mac system will use the monitor profile, so you can see the color change of the system immediately by manually switching the color profile of the monitor on the Mac.

Next, we use the professional monitor SW270C of BenQ in my hand, and let the commonly used picture-related software under the two systems load an Adobe RGB picture, and compare it with the real camera shooting. As a professional photographic display, SW270C of BenQ supports 99% Adobe RGB, and has been calibrated by hardware, and the color accuracy is △E≤2. Moreover, it has color temperature uniformity technology, and the consistency between the periphery and the center is quite good. The display effect used for testing is credible.

The first is mac OS, and the system version used for testing is catalina11.15.6. We save a tulip picture in sRGB and AdobeRGB modes respectively, and the picture contains a lot of green parts, because in Adobe RGB and sRGB color space, the biggest difference is green. Open the picture in Adobe RGB format first, and I also set the color gamut of the monitor to Adobe RGB. The result of shooting the screen with a camera is as follows:

The above picture does not show the situation of sRGB film industry, which is basically the same. In this way, under Mac, the display effect of different software is correct. There is no color difference. Just use it directly.

The situation under Windows is much more complicated. Let's take Win 10 as an example. First of all, if the monitor is set to Adobe RGB, the Windows desktop, interface and desktop background are all oversaturated. If you want these displays to be correct, please set the color mode of the display to sRGB mode, which wastes the color gamut advantage of AdobeRGB. But don't worry, we will introduce several softwares that can accurately display Adobe RGB colors in win system.

The color mode of the monitor is set to Adobe RGB. Let's open the picture in Adobe RGB format with different software first. The effect is as follows:

By comparison, we can see that the display of the three softwares in the bottom row is oversaturated. Next, we use the same software to open the sRGB format picture, and the effect is as follows:

There is no difference in the result. The above three softwares can display normally, but the following three softwares are still oversaturated.

The main reason for this phenomenon is the problem of color management in Windows. Windows's own desktop, interface, desktop background and other programs will ignore the color profile of your monitor. No matter what monitor you connect, it will be used as the sRGB monitor. After loading the picture, it will convert it into sRGB according to the embedded color configuration of the picture and send it to the monitor. We know that the RGB value of the same color is smaller in sRGB than in Adobe RGB, so incorrectly displaying sRGB as Adobe RGB will lead to oversaturation. This is why the Windows interface is supersaturated.

Therefore, sRGB pictures can't solve all the problems. If you use a wide color gamut monitor under windows, if the configuration is incorrect, there will still be color cast problems.

For software other than Windows itself, the situation will be more complicated. Although Windows provides the function of color management, the system does not deal with the problem of color management, but leaves the mechanism of color management to the software itself, so there are many problems.

The first kind of errors are light and shadow, Win 10 photos, IE, etc. Their behavior is the same as that of the Windows interface. When loading a picture, they will recognize the color configuration file embedded in the picture, ignore the color configuration of the display, and directly convert it into sRGB and send it to the display. Cause all pictures to show supersaturation. What's more, some of this kind of software actually claims to be special software for photographers to look at pictures and support color management.

Another mistake is drawing and looking at ACD See quickly. This software loads the picture, regardless of the color profile embedded in your picture, directly reads it as sRGB, and then sends it to the display for display. The behavioral results of such software are as follows:

The effect is as follows:

Although this kind of software shows the correct time, it has no reference value at all It can only be said that a blind cat meets a dead mouse, which is the same as a clock that doesn't walk.

According to the above test, a large part of software under Windows won't care what color space your monitor is in. Think of you as the monitor of sRGB. Some software will parse the color profile embedded in the picture file and convert it into sRGB. Some software directly ignores the color profile of embedded images.

Seeing this, maybe some photographers will have new doubts. Since there are so many problems in using a wide color gamut monitor under the Windows system, I simply don't buy a wide color gamut monitor. This practice can be said to be because of choking. In fact, we can avoid these problems brought by Windows system from two aspects: the software used after purchasing the wide color gamut monitor and the choice of model when purchasing it in the early stage. Below, I'll give you some solutions.

There is nothing wrong with Adobe's support for wide color gamut displays. The following software can support wide color gamut display after simple setting.

1 HoneyView: also called bee picture browser, compact and easy to use. It is worth recommending.

See 2 ACD: Note that its quick browsing function does not support color management. Full-featured but huge. I have tested Pro 7,2020 Ultimate and Pro 12.

3 IrfanView: you need to install a plug-in to support it.

Take HoneyView as an example, the settings are as follows:

If you are a time-lapse photographer, the latest LRT 5.6.7 can also configure the color space of the display, as shown below, which is not supported by version 5.4.

After selecting the monitor in the early stage, you can save the software settings mentioned in the previous section. In order to avoid various problems when using wide color gamut mode under Windows system, you can pay more attention to the following points when purchasing monitors in the early stage.

1, does it have a wide color gamut?

2. Is there a sRGB color gamut?

3.3. Whether parameters such as brightness contrast can be adjusted in SRGB mode.

In fact, the different color gamut provided on the display has different uses, and the display that only supports a single color mode will make the user very passive. In addition to the problem of over-saturation of picture browsing, video playback is also a problem that will drive you crazy. Once the adjusted videos in Pr and Ae are opened by other players, they will be oversaturated, especially those with high color purity, such as sunrise and grassland, because the color adjustment of general videos requires DCI-P3 color gamut. In addition, in daily communication, you will often encounter pictures sent by friends through WeChat screenshots, which will lead to supersaturation, because most of the color gamut used in general network circulation is sRGB.

So it is not enough to support only the wide color gamut mode or only the sRGB mode, because other modes are equally important. The BenQ SW270C I am using now provides a variety of color modes to choose from, such as Adobe RGB, sRGB, Rec.709, DCI-P3/Display-P3 and M-Book. Therefore, we can usually switch it to sRGB mode to prevent the Windows interface from being oversaturated. If we need to retouch the picture, we can switch it to Adobe RGB mode. This not only avoids the oversaturation problem of Windows desktop, but also provides a higher color gamut for photographers to retouch.

In addition, this problem can be effectively avoided by using a display that supports two-color fields. BenQ SW270C also provides a dual color gamut mode, which can preview the same photo in different color spaces and compare the display effects of different color gamuts on the same screen. So you can use sRGB mode on one side and AdobeRGB mode on the other, which is foolproof. In addition, the monitor also provides an external OSD controller hotkey Puck G2. I can save the settings of customary parameters such as brightness and contrast, and I can switch the color gamut at any time with one key, so the humanized design is very convenient.

Under Mac, the wide color gamut display can be used at will. Under Windows, in order to avoid over-saturation of the system interface, please switch the color mode of the display to sRGB when using the wide color gamut display, and switch the display to Adobe RGB mode when retouching. Because PS can set any color mode, in the end, no matter what color format pictures are output, you should use a picture browser that supports color management, such as ACD See and HoneyView. It is also important to remember that these softwares need to be set up correctly before use. If you are still worried about color difference, it is recommended to use a wide color gamut display with dual-color domain function, with sRGB mode on one side and AdobeRGB mode on the other, which is foolproof.

Of course, compared with the later efforts in software debugging, it is the most worry-free and labor-saving to choose a display screen that can convert multiple color gamut and support dual-color domain mode in the early stage. Like the SW270C I am using, except for the above points, its 10bit ips panel provides a wider viewing angle while enjoying the more natural color transition brought by 10bit. At the same time, the color accuracy of this monitor is also excellent, △E≤2, basically no human color cast, and it supports hardware calibration. It has been calibrated before leaving the factory and can be used directly. Compared with software color correction, the parameters after hardware color correction are directly stored in the display hardware, even if the system is reinstalled or even the host is replaced. SW270C also provides a brand-new technology for unifying brightness and color temperature. The screen is divided into 25 areas when it leaves the factory. By independently calibrating the brightness, color temperature and color scale of each area, the accurate unification of colors everywhere on the screen is realized. Whether in the evaluation of professional laboratories or in my actual use, the effect of this monitor is very good. If you use Windows system and want to start with a professional photographic display with wide color gamut mode, you might as well start with my SW270C.