A quick-tip tutorial on how to isolate emission shader output to the front or backface of a light panel.
Blog post: http://goo.gl/Pw1xiC
PS - after running so many takes with this quick little video, I finally finished it and then realized I left out the coolest part…adding a different light source/setting on the backface. Doing this is very easy and simply requires wiring up another shader to the second Mix Shader input as shown below: