This is a popular science essay introducing the accuracy of color gamut.

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Presumably, when boys buy a monitor, they often find that the product interface of the monitor has written how many color gamut the monitor has, including 99%sRGB, 99%Adobe RGB and 95%DCI-P3. Some monitor titles will write that they are wide color gamut monitors. What exactly is this color gamut, and will it affect our experience? In addition to the color gamut, some monitors will also mark their own color accuracy on the title? △E≤3, some people will say that their monitors have their own factory calibration. What is the concept of the number after △E? In this video, we will take you to know more about the color gamut and the related contents of the color gamut. Before explaining, we need to know something-the horseshoe diagram of color gamut.

If you have studied physics in high school, you should know that light is a kind of wave, and wave has the concept of wavelength. The human eye is the organ that receives this wave. More precisely, it should be cone cells in the retina. These cones can't recognize all wavelengths of light, but only a certain range of wavelengths. The numerical range of this wavelength is almost 380-780nm, which is called visible light. Light with a wavelength less than 380nm is called ultraviolet light, and light with a wavelength greater than 780nm is called infrared light. Ultraviolet and infrared rays are invisible to the naked eye. We map the color information and brightness information of all visible light to the screen through certain mathematical transformation, and get such a horseshoe diagram of color gamut, which represents all colors that the human eye can recognize. This color range space is called cie color space. The function of the monitor is to convert the data in the computer into color light that you can see, that is, to turn digital information into color information in the real world. An ideal display should be able to restore all colors in CIE space, but our display technology can't reach this height. As mentioned in the Working Principle, Advantages and Disadvantages of Organic Light-emitting Diodes and LCD screens, at present, the colors of displays are mixed by three sub-pixels, so the limit of one display color is the maximum brightness of red, green and blue, while the other colors mixed by red, green and blue can only be in the internal area where they are connected at three points. This triangle represents all the colors that the display can display. Official website is called the color gamut of the display.

That is to say, the color gamut value is the concept of color richness that the display can display. The wider the color gamut, the richer the colors that can be displayed. On the contrary, the fewer colors can be displayed. Because everyone's display can cover different color ranges, our photographic equipment can store different color information. So in order to unify all walks of life, different color codes have been determined. Taking a certain area in the CIE color coverage area as a scale, the color information is stored according to the scale.

Common color spaces are sRGM, NTSC, Adobe rgb and DCI-P3. At this time, it is easy to understand by looking back at the product interface of the monitor. 99% sRGB means that it can display 99% colors in sRGB space. Therefore, when referring to the color gamut of the display, you need to carefully look at the label behind the number, not the number in front. If you want to compare the 99%sRGB display with the 95%DCI-P3 color gamut display, it seems that the former has a wider color coverage, but in fact the latter covers a much wider color gamut than the former.

At this point, I believe many people will have a new question, that is, since my monitor can only display colors in a certain color space, why can I see colors outside the triangle color space on the horseshoe diagram of color gamut on my screen? The reason is also very simple. The colors that cannot be displayed on the display will be forcibly displayed according to a certain mapping. That is to say, the color gamut horseshoe diagram you see on the screen is no longer the color it really should have. The color space of triangle on the color gamut horseshoe diagram is not an absolute concept, but a relative concept, which is relative to the size and proportion of the horseshoe diagram itself. Since a monitor with a wider color gamut can display more colors, if you choose a monitor according to this idea, the wider the color gamut, the better, right? Well, if you think so, if you buy back a monitor with a very wide color gamut, your experience is likely to be backward rather than forward. Why?

Here are some contents related to color management. Limited to space, I won't talk about it for the time being and put it in the next article. What you need to know now is that the monitor you bought can give you the best experience at the moment.

Speaking of color gamut, let's talk about color accuracy now. In fact, the concept of color accuracy is very easy to understand. Color accuracy refers to the accuracy of the display in the color gamut coverage. For example, if you want to show blue, the monitor will show you cyan; If you want to display red, it will display orange. This is the expression of color difference. The parameter to measure color difference is called e value. The smaller the e value, the smaller the color difference and the higher the color difference. The reference of δe value is generally the reference average δe value and the maximum δe value. When the display with standard deviation of color displays the picture, the color will be incorrect and appear color cast. If you have bought a monitor with poor color accuracy, don't worry. We can use the color calibrator to calibrate the color of the display later. Just stick the color calibrator on the screen, and then run the color calibrator supporting software in the system, which will make your screen display some colors, capture these colors with the color calibrator, calculate the color deviation number E of your display, and then generate a color calibration file through some formulas and algorithms. You just need to import this file into the system. If the software or game you use supports calling this file, the color you finally display will be calibrated by the color calibrator. But the calibration is only based on the color mapping on the software level, and the quality of the panel itself cannot be changed by the color calibrator. Although the E value can be partially reduced after color correction, it cannot be said that a display with particularly poor color accuracy can become a display with excellent color accuracy. And now many full-screen games, including some software, simply don't support calling color correction files, so if you really need a monitor with better color accuracy, you might as well buy a monitor with lower delta E value and factory color correction.

Generally speaking, the value of △E≤ 1.5 can be said to be excellent in color accuracy, and the price of positioning S-class screens is usually expensive. A display with this level of color accuracy can only be realized when the manufacturer selects the panel and performs factory color calibration on the driving board. In the physical sense, there is almost no possibility of color deviation. △E value is 1.5-3, which belongs to excellent level, and its positioning is A level. Most high-end drawing monitors are basically. This color code is difficult for professionals to see with the naked eye. △E value of 3-5 is an excellent level, and most high-end displays of Class B can be positioned, including high-priced and high-brush esports screens. This level of color coding has little effect on daily use, and simple retouching and color matching is nothing serious. △E value of 5-8 is normal in the color scale, and the positioning is C-level. The mid-range esports screens of most affordable displays are in this range. This color standard is not recommended for drawing and color matching. Ordinary people generally can't distinguish the color cast, but people who are sensitive to color such as retouching can often see the color cast on the screen. The color accuracy of △E value above 8 is very poor, and most people who have a certain concept of the real color at the positioning level will think that this screen color has color cast problems at first sight. Many cheap entry monitors below 800 belong to this category.

Unless you are a professional retoucher or video colorist, generally speaking, you don't need to care too much about the performance of the color code, because compared with ordinary office workers and ordinary gamers, the color code has a lower priority in front of other parameters, and you should take into account the resolution, refresh rate, response time and panel type. All the related contents about color gamut and color standards are introduced here, hoping to help boys to make fewer detours when choosing screens.