What are the dithering techniques in photography?

To be precise, shaking black cards and shaking cards is a technique that will be used when shooting scenes with particularly large contrast, such as sunrise. At this time, in order to make the dark part of the film have enough exposure and the bright part will not be "overexposed", a card is blocked in front of the camera (corresponding to the bright part position) and kept shaking to reduce the sensitivity of the bright part.

Technology that has existed since the film age.