Light Preview area

Used only with Spot lights when they project images or gobos, the Light preview area shows you what the shape of the projection looks like.

Setting Description
RGB/Alpha options Lets you view either the full image or the alpha channel of any image projected by the Spot light.
Light Preview When no image is selected, the light preview shows a white circle. If an image is select in the media menu, it is shown here.
Media menu Use the Media menu to select an image to be projected by the Spot light, depending on whether you have activated the Draw Ground Projection option, or the Draw Volumetric Light options. For example, if you have only selected Draw Ground Projection, the selected image is shown on the ground. If you have selected Draw Volumetric Light only, the light beams are shown. See Projecting images with lights for more on how to use lights to display images.
Reset/Save as default The Reset and Save as Default buttons let you save modifications you have made to a light’s settings to create a new default light. Once a default is set, every new light added uses this custom setting. For example, you can save a Spot light’s intensity, cone angle, and fog options as a default, and then all lights that you add to the scene use these settings. You cannot save Interest, Up Vector, or Media settings as defaults. Saving default settings is useful if you need several lights to use specific custom settings. See Saving light settings as defaults for more about creating a new default light setting.