On 2012-11-26, at 7:27 AM, Iliah Borg wrote: > I made a specific series of experiments yesterday, shooting black trap and > lens cap, using same shutter speed; with several different cameras. The > results are very similar given the cameras have no light leaks (viewfinder > covered during the exposure). I'm afraid black trap data is skewing the > profiles as it represents bias more than anything else. I think the proof of this pudding may lie in the eating...I'll run some experiments of profiles before and after deleting the row out of the .ti3 and see what it does to the resulting profiles. I do seem to recall that the RGB levels of the trap changed with the camera exposure...but, then again, I wasn't bothering to cover the viewfinder. (However, the whole room behind the camera is black, so there shouldn't be any significant stray light getting in that way.) b&