Area lights are a feature of the mental ray renderer. Instead of emitting light from a point source, they emit light from a broader area around the source. Area lights create soft-edged shadows. This can help improve the realism of your rendering.

Scene rendered with area light turned off

Shadows are ray-traced.

The yellow cube indicates the light's location.

Scene rendered with area light turned on, showing soft shadows

The light in this rendering is a 2D (spot) area light.

Scene rendered with a 3D (omni) area light

The light uses the default radius of 20.0.

NoteTo render soft-edged shadows, shadows must be ray-traced, not shadow-mapped. See the Render Setup Dialog Renderer panel Shadows & Displacement rollout.

Area lights support global illumination, caustics, and other features of the mental ray renderer.

TipArea lights take longer to render than point lights. If you are interested in creating a quick test (or draft) rendering, you can use the Area Lights/Shadows As Points toggle to speed up your rendering. This toggle is on the Render Setup dialog Common panel Common Parameters rollout.