Vignetting Driving Me Nuts, Looking for Advice

[Harry]

Just for reference, this is @ArnoG’s explanation of the reasoning behind this theory, I presume it hasn’t changed:

Integrating sphere as a uniform backlight

Hi all, As mentioned in the first post in this forum thread, a finite planar light source (such as an LED panel) will always result in an inhomogeneous light distribution on film. A planar light panel a give a homogeneous light distribution on film, provided it is infinitely large compared to the film, which is not practical for table-top solutions. It took me a while to get this done, but I just calculated the brightness inhomogeneity on a film that results from using a planar light source tha…