Just for the sake of the fun of it (it IS fun playing with LuxRender, isn't it?), here's some info some of you might like.

First we have some addons for LuxRender which will allow you to export your image to .jpg or .tif directly from the Luxrender GUI. Second, and a few posts down, we have something called CRF's or Camera Response Files. I'll show an example of the usage of those in a bit.

http://www.luxrender.net/forum/viewtopic.php?f=30&t=4869

Laurie