I found this image somewhere on the Internet:
It was made with Cinema 4D and some special renderer. I decided to try create somethings similar using our favourite Blender and Cycles.
To achieve a nice rainbow refraction I created the following nodes setup for lens material glass:
And here are my render settings and my best result (with sampling = 48):
I tried to set more sampling (256), but the result doesn't seem to be better, just more noise light:
In addition, I tried to use volume scatter in the world nodes, but this gives only noise in the all scene, even no light is seen through the lens:
Also, my mirror made with simple glossy shader doesn't seem to work nicely too as it can be observed from pictures above – it doesn't reflect light to the left side of the image. It just reflects the scene:
Here there are it's material nodes:
The lens was made from subdivided ico sphere, and the lens, the light, and the mirror (made with a cube) have the same Z coordinate.
So, is it possible to achieve more realism close to the first picture? And how?