This looks like a plug-in that photographers would find useful. I did one try with it and can see potential there.

http://registry.gimp.org/node/25479

It's found in Filters > Generic > Luminosity Mask

I duplicated my image layer then ran the plug-in on it. It created a mask on the active layer and I didn't change very much in the dialog. Checked Darks and moved the slider to -0.5. Then I applied the mask, changed the masked Layer Mode to Addition and here are the results. Original photo on left.

That looks good, you can see the detail in what used to be shadows. I think the original has more depth and is slightly more interesting, but it looks like a good plug-in, works well.

I think with practice and use it could be really utilized well. Mine was a quicky tour just to see what happened.

That does look like a good plug-in. It brought out all the darks without losing its depth

i can't find the plugin

Click the link in "O's" post then scroll down until you see gimp-luminosity-mask-py.txt. Remove the .txt on the end

thanks molly your a lifesaver

Be sure to remove .txt extension. The real extension is .py

Thanks for the link O.
Very useful script.
Gerard.

O, Thanks for the instructions. I had downloaded it but wasn't sure how to use it. For most of the pictures I have tried it on, I found that using your settings, but using screen mode instead of addition, gives a little more moderate effect without overemphasizing the brights.