I'm giving DPUG another go after several years. I think this question belongs here. I'd like to make a reflective scan of a 4x5 Stouffer step wedge alongside a 4x5 negative. I would scan the two together in one pass without any corrections. The step wedge I'm looking at is the upper right image on this page: Stouffer Industries. Part number TP4x5-21. My scanner is an Epson V500. Can I determine which zones different areas of the negative falls into by hovering over that area, looking at the RGB values, and then hovering over the step wedge to find the closest match? Is my thinking accurate? Thanks.