What does a black card for photography mean?

Photographic black card is a tool for photometry. It is generally a thick black card with white numbers, lines and rulers printed on it. It can help photographers to measure the correct exposure and determine the shutter speed and aperture size under different lighting conditions.

The function of the black card is to help the photographer control the exposure reasonably in order to get the correct photo effect. In the long exposure such as night shooting, the black card can also get more accurate exposure time. At the same time, because the black card has obvious contrast characteristics, it can be used to check whether the photographer is aiming at the white balance correctly.

To take pictures with a black card, you need to put it in front of the scene to be shot, then aim the camera at the black card and measure the light. In the process of photometry, make sure that the black card and the camera are in the same position, and then use the measured value to adjust the shutter speed and aperture size. It is worth noting that because the contrast of the black card itself is related to the contrast of the photo itself, it should be adjusted according to the actual situation when using the photographic black card.