Teaching you how to choose a monitor hand by hand Ⅱ.

发布者:Admininstrator 来源: 发布时间:2016-11-04

Teaching you how to choose a monitor hand by hand Ⅱ.


Does small sized monitors need to be full pixels?

Pixels of course, the higher the better. However, the smaller the size, the higher the pixel, which means the higher price,  The basic property of a small-sized monitor is to view the composition, but that does not mean the pixels are not important. The same 800x480 pixels, displayed on a 5 "screen, and the image looks very fine, but if it is displayed on a 7" monitor, the image quality is slightly grainy. Because in a certain case, the larger the display size, the dot pitch is greater and the image is less clear, it is like we are painting on silk and linen , the effect is much different. Therefore, when conditions permit, try to select the high definition monitor, is conducive to observe the level and detail of the screen, especially when view images only by small-size monitor , it is particularly important.


Does the little size monitor need color calibration ?

This will be decided according to your current equipment configuration.In a big-budget production ,generally there will be a DIT team or video engineer in charge of image index adjusting and control . However , there will not have this kind of staffing configuration in the most of film's production crew . Therefore , firstly we suggest the crew to own a full HD multi-function monitor over 17’ with color management system . Not only it can be used by director at the scene , but also can provide accurate reference information for the director of photograph , art director ,lighting engineer and other station crew .  If you have not enough money to buy a big size monitor or just viewing image by little size monitors , It will be very important for a monitor to have the accurate color restoration in this condition . What color restoration we are talking about is not only about RGB balance , but also another important index --Gamma . If the deviation of Gamma is large , it will cause the distortion of image brightness and contrast and then cause distortion of chroma . If the gray scale data tolerance range is over REC709 , it will also cause image deviation in the condition of the video input of Log mode . If we view one picture by a self -define Lut with the monitor never been calibrated , the accuracy of color restoration you will not imagine . Of course ,it will no matter that the monitor with 3D-LUT function or not if the monitor is just used for image viewing by the photographer .

Will the size of original color gamut affect the color restoration of the monitor ?

There are not many small size monitors can meet REC-709 color gamut as you can see according to lots of testing data and also included the small size monitors from our company . This maybe caused by the elements of production cost or technology and also the LCD monitor panel manufacturers can not do it at present .However , the white balance of small size calibrated monitor is accurate . Even though it can not reproduce the target color gamut of REC709 by 100% , it will not have color deviation as a whole at least. ( that is deviation ) phenomenon . As diagram show (*). Although the saturation of RGB will have a deviation by 80% , the chrome hue restoration is normal within 80% and it will not affect integrity of integrated color recording . That is because the determining factor of high and low saturation level of original signal is not monitor but the video cameras .

  In the diagram of REC709 color space as the picture show , the white square frame is target data and the central dot is testing data .  If the central dot is totally placed in square frame , it shows that the color gamut and hue is compatible with the target value . Conversely, the saturation will be in low level or the color is deviating .

then how can we check and learn whether the original color gamut and hue of a monitor is normal if we don't have any professional inspection equipment. It can be done by subjective evaluation as follow :

 1. Firstly the cameras will be adjusted in REC709 recording mode.
 2.Let the person under shot take the red , green ,blue cards with 100% saturation or the goods with high saturation  in the condition of standard color temperature illumination .
 3.Luminance waveform is placed in the level of 50IRE or about 0.4V and adjust white balance .
 4.The person under shooting and color checker will be in the same picture scene , then observe the skin color of the person under the shooting from the screen of monitor tested .

If the color reproduction of skin and color checker performance normally, it can indicate the color gamut and hue of this monitor are normal. If only the color reproduction of skin presents normally but color checker is unsaturated, it proves the original color gamut of this monitors can not reach the target color gamut. But the color trend (hue) is basically normal. And if the skin color reproduction is far away from the target, then it can indicate the hue of this monitors is weird. Even though the original color gamut is big enough, the monitor can’t be used as a professional monitor either.