What role does the blackboard play in photography?

The blackboard is called a shading board, which can block the propagation of light in a specific direction.

Shade: refers to an opaque material between the range where light is irradiated and the range where light is not intended to be irradiated.

Shading plates are usually used in backlights to prevent light from directly entering the lens and causing glare. In the market, artificial light source is used for lighting, and the shading plate is generally located between the flash and the photographer, so that the light can shine in the desired direction without causing glare.

Moreover, not only black can be used as a shading plate, but also a soft light plate can be used as a shading plate to reduce the light ratio and soften the light quality in the sun.

Common photographic accessories with the same function include hood, pigmouth tube and so on.

lens hood

Pig mouth bundle tube