Today we decided to do Lillies 10 month shoot. I had the same exact setup as I did last shoot. So I decided to take the gel holder that was holding the gel over the SB-24 main key light and strap it onto the Vivitar DF400mz on the back drop. I put a Rosco #26 Light red gel on the back flash and started testing. The trick was that the front key light needs to have less light than the back so it does not over power the gel. I think the posibilities are now endless. I would recomend testing this to all strobist out thier.

Vivitar DF400MZ boom pointing at backdrop with #26 Light Red gel
Nikon SB24 shoot through umbrella upper camera left

Strobist:
Vivitar DF400MZ 1/1 power on boom pointing at backdrop with #26 Light Redgel
Nikon SB24 1/4 power shoot through umbrella upper camera left

Camera: Canon EOS 20D
Exposure: 0.01 sec (1/100)
Aperture: f/5.6
Focal Length: 66 mm
ISO Speed: 100