In optics, a diffuser is any device that diffuses or spreads out or scatters light in some manner. Optical diffusers use different methods to diffuse light and can include ground glass diffusers, teflon diffusers, holographic diffusers, opal diffusers, and greyed glass diffusers.
Diffusers in photography
Flash diffuser
A flash diffuser spreads the light from the flash of a camera. In effect, the light will not come from one concentrated source (like a spotlight), but rather will spread out, bounce from reflective ceilings and walls, thus getting rid of harsh light, and hard shadows. This is particularly useful for portrait photographers, since harsh light and hard shadows are usually not considered flattering in a portrait.
Diffusion filter
A diffusion filter is used in front of a camera lens to soften the image of the scene being shot.


