The recent "Red rice Note 2 screen event" has triggered the views of people from all walks of life in the industry, including many netizens, on mobile phone screens. As an evaluation agency, we do not discuss the right or wrong of Xiaomi's propaganda. We only discuss the performance of the screen itself here. At the same time, we find that there are some deviations in your understanding of the parameters of the mobile phone screen. Here is a brief introduction to science.
About the color gamut of the phone screen
The color gamut range of wide color gamut mobile phones in the green part is much larger than that of conventional sRGB
First of all, let's talk about the color gamut. The concept of color gamut is very complex. Most people think that "The wider the color gamut, the better. The wider the color gamut, the more colors can be displayed." The first half of this sentence is half right, while the second half of the sentence is totally wrong.
The current reality is that we usually surf the Internet, watch videos and pictures, and the color gamut standard used for display on computers and mobile phones is sRGB. The so-called wide color gamut Adobe RGB and NTSC color gamut are only used in professional fields, even if you use A 100% NTSC color gamut/Adobe RGB screen uses this device to access the Internet. What you see is nothing but the content projected from the sRGB color gamut to the NTSC/Adobe RGB color gamut.
Larger range of Adobe RGB color gamut
Because the range of these two color gamuts is larger than sRGB, for example, when you see the green color coded as (0255,0) on the Internet, if the color gamut range just covers 100% of sRGB color gamut, you will see the "green" that the web page producer wants to express. If your screen covers 98% Adobe RGB at this time, because of the wide color gamut, the system will code (0255,0) When the green color is projected onto 98% Adobe RGB, it becomes a more colorful green color. At this time, the content you see is no longer true.
In terms of sRGB alone, naturally, the more sRGB is covered, the more accurate the color will be displayed. But if the color gamut of the screen is too large, far beyond the sRGB range, and also covers more than 90% of Adobe RGB/NTSC, the displayed color will definitely be too rich (oversaturated). Similarly, if the color gamut is too low, the color will also be inaccurate, So the color gamut of the mobile phone screen is not the bigger the better, but the closer to the 100% sRGB color gamut, the more accurate the display color will be.
Note: (The color gamut of iPhone 6/6 Plus is very close to 100% sRGB, while Samsung's SUPER AMOLED color gamut is extremely wide, but in the Galaxy series, you can adjust the screen color gamut, that is, the color gamut range In this mode, the ultra wide color gamut is reduced to nearly 100% sRSG, so the color restoration of Galaxy S6 in the basic mode is also quite accurate.)
The red, green and blue sub pixels can be seen when viewing the screen with a magnifying glass, microscope and other equipment
Now let's talk about the big mistake of "the wider the color gamut is, the more colors can be displayed". When we look at the mobile phone screen and the computer screen, we will see a parameter called "16 million colors". The so-called 16 million colors refer to the 16 million colors that can be displayed on the screen, that is, the 8 bit screen. On digital devices, Each pixel of the screen is composed of three sub pixels: red, green and blue, and each of them (red, green and blue) can display 256 different colors (to the 8th power of 2). The 256 red, 256 green and 256 blue colors are combined, that is, 256 * 256 * 256=16.77 million, which is what we call 16 million colors.
Galaxy Note5 uses Super AMOLED wide color gamut screen, but still only 16 million colors
On computers/mobile phones, they exist in the form of codes. For example, (0,0,0) represents black, (255255255) represents white, and (0255,0) represents pure green. The problem is that the highest specification of all mobile phone screens on the market is only 16 million color screen panels. They can only display 16 million colors, but have a wide color gamut and a conventional color gamut, So the wide color gamut screen also displays 16 million colors, but the 16 million colors they display are different from the normal 16 million colors of 100% sRGB, which means that the saturation we mentioned above will be higher. Because of the wide color gamut, the green of the same point (0255,0) will be displayed more green in the wide color gamut, while the 100% sRGB will be displayed normally. Professional display equipment will reach the so-called 1 billion colors. Each type of screen (red/green/blue) can display 1024 different colors, that is, 10 bit screen panel. This wide color gamut screen is more meaningful.
It is worth mentioning that the screen with wide color gamut has a wonderful effect when watching animation. Because of the high color saturation, some users will feel that the effect is good (although the color has gone against the original intention of the production team). Of course, the color gamut is just a parameter in the screen, and the quality of the screen involves many aspects and parameters. This simply means that the so-called "color gamut" is the closer to 100% sRGB, the closer the display effect is to reality, and the wide color gamut screen will not display more colors.
High configuration Tianma screen of Hongmi Note 2
Next, let's take a look at the screen data of the high configuration version of Hongmi Note 2, the nut phone and Meilan Note. Both the nut phone and Meilan Note use the 5.5 inch 1080P screen of Sharp/Youda, while the high configuration version of Hongmi Note 2 uses the 5.5 inch 1080P screen of Tianma/Youda (our four high configuration versions of Hongmi Note 2 are all Tianma screens after inquiry).
In terms of parameters, although the high configuration version of Hongmi Note 2 uses the Tianma screen, it is not bad in color gamut, color temperature, and color deviation. It has greater advantages in color deviation compared with the Sharp/Youda screen of Magway Note, and the default color temperature is closer to 6500K in color temperature, The coverage of the sRGB color gamut is also better than that of the Magic Blue Note, whose highest brightness is far better than that of the red rice Note2 and nut mobile phones.
The nut mobile phone's screen also uses Sharp/Youda. The nut's screen is better in terms of color deviation, while the color temperature is cooler and the brightness is slightly lower.
From left to right, there are Hongmi Note 2 prototype No.1, No.2, No.3, No.4, Meilan Note, and Nut mobile phones
In terms of visual angle, there is no problem with the high configuration version of the Red Rice Note 2 and the nut mobile phone. There is no dead diagonal or color deviation, while the Magenta Note has serious color deviation after tilting, which is very obvious below the diagonal. The last picture is different for each machine because of the shooting angle, The comparison itself is of little significance, but we can see that only the Magic Blue Note has serious color deviation, while other machines only have normal brightness attenuation, of which the nut phone has the best photo location, while the red rice Note 2 high configuration model 1 has the worst photo angle.
When judging whether a screen is good or bad, we can't just look at the screen manufacturer. This is like saying that Samsung's mobile phone must be better than Sony's mobile phone. So is the 1000 Samsung mobile phone really comparable to Sony Xperia Z3? Even though they are big brands, they also have product positioning. There are so many Samsung AMOLED screens on the market, but their display effect is far from that of the AMOLED screen on the Galaxy S6. Similarly, not all Sharp/Youda screens are better than Tianma screens. Tianma screens are absolutely good in data and actual use. As a third-party evaluation agency, We need to tell users more objective and scientific results.
