How to build a ray box to use for a set of refractions/reflections?
I would like to make a 'solid' ray box (not out of cardboard!), preferably with more than one slot, and shine the rays from it to a set of mirrors, prisms, and all different kinds of reflective/refractive materials. The light would bounce off quite a few medias so I imagine it needs to be quite strong, but again, how strong? I know I need a fresnel lense in order to make the rays coming out of my ray box parallel but what is the rule, what distance does the lense need to be from the source of light, and does it depend on the size and strength of the light?
Thank you very much!