how to judge the quality of led display advertising screens?

in order to enable customers to identify the quality of led display products, the following nine important items of led display are synthesized from various perspectives. the first eight items are suitable for general led display, while the ninth item is for small spacing led display.

i. brightness:
maximum brightness refers to the brightness of each primary color of the led display screen at the highest gray level and brightness under a certain ambient illumination. in short, the brightness measured by a light gun in the normal direction when the display screen is set to white 255 by software. for outdoor led display, according to the use of the environment, there will be different requirements for maximum brightness, because in the case of strong environmental light, the brightness of the led display is required to be higher, so that people can see clearly the content displayed on the screen. generally speaking, the maximum brightness requirement of the display screen is lower when it sits in the south and faces the north. as long as it reaches 4000cd/m2, it can meet the requirement. for the display screen sitting in the north and faces the south, the brightness requirement of the whole screen can reach 7000cd/m2. the requirement of facing east and west is the same as that of facing south, because there will be a part of the time when the sunlight will directly shine on the led display. on the screen. in theory, brightness requirements greater than 5500cd square meter brightness is enough.
two. color temperature
when we see that the color of the image is different from the material on the display screen, our picture will be seriously distorted, which is related to the color temperature of the white balance of the led display screen. if the human eye watches the display screen directly, the color temperature of the white balance will be between 6500 and 8000k, which is suitable for tv broadcasting stations. on the display screen, the actual color temperature of the screen needs to be adjusted to about 5500 k, so that the picture on the display screen is real after recording and broadcasting by the camera.

3. refresh rate
the refresh rate refers to the number of times the display information of the led screen sign is displayed in full every second. when the refresh frequency is too low, the human eye will jitter when watching the led display. usually when we use the camera to shoot, we will see the scanning line. usually the refresh frequency of the human eye is more than 300 hz, that is, the refresh rate is only more than 300 hz, there is no sense of jitter when viewing the led display screen with the naked eye. if the camera is used to shoot, according to the different settings of different cameras, the minimum requirement is more than 600 hz to capture the scanning line. high refresh can improve the brightness and color fidelity of the display screen. it can be detected with a digital camera. if it is high refresh, the picture taken by the camera is very clear, there are no snowflakes and scanning lines. this indicator is particularly important when renting screens and television broadcasts.