With this short tutorial I’ll show you how to enlight your scene projectors, flashes, leds, lamps, lights and all those objects that are supposed to emit light thought lenses.
An example: the image below is produced with this technique.
Here there is an object for the projector and a second object for the lens, that is composited to re-create the flare and added to the final image.
In this test i’ve used the render engine cycles, but it works equally with blender internal. Let’s see how to obtain this effect in your scene!