How can I fix a dark spot on my lens in post-production?

Question

I need to fix this in post. Can I do it?

Answer 1

If you shoot an evenly lit white frame you could invert it, adjust the levels so that the non-affected areas of the frame were completely black, and then add the result to the original footage. It might take some tweaking of the levels to get it right.

Answer 2

It depends, which software you want to use. The easiest one is probably After Effects, which has a function to replace an object completey by analyzing the background.

But you could as well try to set a new alpha layer on the film over its complete length, masking the dark spot and light the spot area up a tiny little bit.

This might result in a loss of contrast and sharpness, though.