Light objects have the same attributes and methods as Layer objects, except for source, effect, mask, width, height, anchorPoint, scale, opacity, audioLevels, timeRemap, and all of the material properties.

pointOfInterest

Return type: Property [3].

Returns the light’s point of interest values in world space.

intensity

Return type: Property.

Returns the light’s intensity values as a percentage.

color

Return type: Property [4].

Returns the light’s color value.

coneAngle

Return type: Property.

Returns the light’s cone angle, in degrees.

coneFeather

Return type: Property.

Returns the light’s cone feather value as a percentage.

shadowDarkness

Return type: Property.

Returns the light’s shadow darkness value as a percentage.

shadowDiffusion

Return type: Property.

Returns the light’s shadow diffusion value, in pixels.

David Van Brink provides an instructional blog post and sample project that show how to use expressions with lights: www.adobe.com/go/learn_ae_ominoflashing.