What is the scientific name of flashlight in photography?

Tindal effect (English: Tyndall effect), also known as Tindal effect, Tindal effect, Dinsey effect, Dinsey effect. When a beam of light passes through the colloid, a bright "path" can be observed in the colloid from the vertical direction of the incident light. The principle is that light is scattered by suspended water vapor and colloidal particles (such as emulsions and suspensions). Tindal effect is named after physicist John Tindal, who was the first scientist to study this phenomenon deeply.