We are running a setup that consists of an extra wide screen that uses two edge blended beamers. It's been running for some months, but I never managed to really configure the soft edge to look nice. There was always the problem that the overlapping area was too bright and we fixed it by lowering the overall brightness of the beamers - resulting in a really bad image.
So I started to play around with the Black Level Compensation but I can't get to an acceptable image. A dark image causes the non-overlapping area to appear brighter than the overlapping area, so I think that I over corrected the black level. But a bright image makes the overlapping area appear brighter! I don't know what I'm doing wrong or how I should configure the values. I attached two example images of the screen. How should I configure the soft edge so a uniform image is shown, no matter what image is displayed?