>>6209729Now since I'm not working with an original clean image and just re-using a compressed jpg file over and over, this doesn't look very nice, but the last image is a little too bright with the white areas on account of the slapdash use of the Levels tool to illustrate the last point about non-white bounce lighting.
The Shadows/Highlights tool (I don't know if there's a Gimp equivalent) can either bring out details in dark areas by lightening the shadows, or make white surfaces more defined by reducing the glare they're putting out.
This is a good way to make mocs with lots of black or white pieces "pop", because rather than being a clump of pieces without detail, suddenly you can see the contours of every surface.
One downside of this is that using it on dark areas can produce a lot of noise.