I have about 10 images of plates I am taking for posting on Ebay. The concave bottoms focus more light back at the camera giving a little more blown out area (see example). My grandmother, who is selling the plates wants the colors balanced instead of writing a note as to why this is happening. I tried using Gimp to dodge/burn the lighter areas and while it was kind of working it didn't give a consistent effect. I tried making a circular mask to dodge/burn but certain areas are brighter than others and so it wasn't working nearly as well as I hoped. How do I fix this? My options are:
A: Adjust the lighting being used (we were using light coming through a window and a reading light aimed at the ceiling) and/or
B: Some method of editing in Gimp I have yet to figure out that will let me make the correct adjustments.