Wednesday, September 21, 2011
Flash Color Correction: A Quick and Dirty Example
Above: a quick demo of the effect of color correction gels on a hotshoe flash.
You can put any sort of gel on the head of a hotshoe flash. Attach a blue gel, for example, and you can turn a white wall into a blue background. Easy.
The more refined skill to master, though, is using color correction gels.
The idea: put the right gel on your flash so that the light from your flash matches the ambient light in a location.
Shooting in someone's living room at night? You're probably seeing tungsten-balanced lights. Add a Full CTO (Color Temperature Orange) gel and the light from your flash will change from daylight-balanced (5500k) to tungsten-balanced / indoor (3200k). Or, maybe you need a bit less: a 1/2 CTO or just a 1/4 CTO.
Shooting in an office? Add a Full+Green and your flash will better match the greenish light the overhead fluorescents probably provide.
Shooting in open shade outside? The light is probably quite blue in color temperature ... so put a 1/2 CTB (Color Temperature Blue) on your flash.
Now, that's step one.
The quick example above is a reminder how the gels change the look of the light -- in a shot that is white-balanced for about 6000k. (That's not a magic number -- it is just a match for the light present for the first, ungelled shot.)
So, you've done step one: you've matched your flash to the color temperature of the ambient light.
What's step two? Change your white balance to match.
So, let's say you are in a living room at night: gel your flash (with CTO) and then set your White Balance to 3200k (or "indoor" or "tungsten).
Try it out.