Hmn, but I’d expect auto-exposure to make up a global, frame-wide constant, linear factor, just like exposure time in foto.
For now, I found that it doesn’t seem to have to do with texture encoding:
the 10 rings should be easily (and all similar) distungishable, but the outer ones are hard to see.
Used this material:
So the problem could be caused by treatment of emissive color in the generic material exit node. Haven’t yet focussed on specialized tone-map, and the postprocessing volume in 3rd person example is there but at defaults (almost everthing disabled).