Indigo accurately simulates the physics of light which create many realistic effects that otherwise would have to be manually created. Because of this, it takes far less set-up time than traditional biased or 'global illumination' renderers. Simply creating a glass object and a light will produce beautiful caustics.

Effects such as:

* Depth of Field – the depth of field (DOF) is the portion of a scene that appears acceptably sharp in the image.
* Spectral effects – as when a beam of light goes through a prism and a rainbow of colours is produced
* Refraction – as when light enters a pool of water and the objects in the pool seem to be “bent”
* Reflections – from subtle reflections on a polished concrete floor, to the pure reflection of a silvered mirror
* Caustics – as in light that has been focused through a magnifying glass and has made a pattern of brightness on the floor