Diffusion Panel
A frame holding translucent fabric, used to enlarge and soften a light source placed behind it.
Measured in
cm
In depth
A panel converts whatever light passes through it into a source the size of the fabric, so a bare head two metres behind a 1×2 m frame becomes a very large, very soft key. Because the light and the panel are separate, the softness and the falloff can be adjusted independently — something a fixed softbox cannot do.
Examples in practice
A speedlight fired through a 1×2 m panel from a metre behind gives light equivalent to a very large softbox.