I think this is my last test on the Coastal Optical 60mm f/4 UV-VIS-IR Apo Macro lens. It’s a simple visual demonstration of light falloff. The camera is a Sony a7 modified for IR by LifePixel, using the Super Color sensor stack filter. I put an Expodisc on the lens and aimed it at a Fotodiox LED 5500K light source. I made exposures at f/4 through f/22.
Here they are:
There’s some noticeable falloff at f/4 and f/5.6, but I don’t consider any of it a problem.