Colour

This work by Adam M is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 2.5 Australia License.

Four of my gels, with a neutral density gel under the lightest blue one.

Pentax K-x - 1/2 sec - f/? - ISO 200 - ~40mm

The gels were placed on a suspended frosted plastic cutting board and an Achiever 300DX flash was manually triggered during exposure, pointing at the white-ish floor underneath the cutting board.

Used GIMP to rotate and crop. Duplicated the layer and used levels to first push everything really bright (to easily select the white around the three darker gels) and then to push everything really dark (to select the lightest gel). I saved these two selections to channels and then inverted the one that represented the lightest gel, subtracted it from the one that represented the other three, and deleted. This gave the pure white surround them (the cutting board was not fully blown out, leaving scratches showing, as well as some of the support). I then adjusted the whitespace to taste, and added space below for a watermark. Scaled and watermarked for the web.

Not the most wonderful of compositions, and trying to balance the really light gel with the darker three wasn't great (and it still looks odd) but boy did I get to try some unusual stuff in GIMP.