Strange round camera lens borders

[srswntr]

Hey folks

I got a lens issue, getting these weird round edges ony my cam view, no idea where they come from. I tried to rule things out, but nothing made them disappear. They move when I change the camera focal length though, so guessing it’s gotta have something to do with the camera setup? I could make them disappear by moving the focal length in far enough, but I really don’t want to change this camera setup. Any ideas where this could be coming from?
Thanks.

[Astrotronic]

Hello,

My first thought is that this is a Vignette applied through post processing. (Although I’m not sure what to make of the sharp edge)

Do you see any difference when turning off Post Processing?

[srswntr]

Thanks for the suggestions. Turning off post processing doesn’t fix it unfortunately, neither does turning off the vignette effect.

[srswntr]

Any ideas anyone?