Since the appearance of Adobe Photoshop Lightroom, Adobe Photoshop CS3 Beta with Camera Raw, then CS3 with Camera Raw 4.x people have been asking about where best to implement luminosity and colour adjustments. Lively discussion of this matter occurred most recently on this website'sForum, and since before that on theApplied Color Theory List(ACTL), a Yahoo membership group run by Dan Margulis.

Mark Segal, a member of ACTL, and contributor to this website, was an early adopter of the new software products and has printed a large number of images from his raw files processed using CS3 and Camera Raw 4 in both Beta and commercial versions. Much of the recent discussions have focused on the question of using Curves and other luminosity adjustment tools in Camera Raw 4 and Photoshop.

Based on his experience using these applications, Mark found a number of positions taken in these discussions surprising, and decided to test the various arguments. He thought the results of this work ...