Fun With Color – Photography Gels and RGB Additive Color
Share:
I was recently at an interactive installation that had three theater lights – red green and blue shining on a white wall.
The kids were fascinated by this – especially with how the colors mixed and how they could make different colors by casting shadows on the wall.
This is a human scale representation of the red-green-blue (RGB) additive color model (the electronic screen you are looking at right now uses the exact same method to reproduce every color you’re looking at).
It also reminded me of some of the really cool applications to use photography gels to have fun with color.
The RGB Additive Color Model
Electronic screens produce colors by projecting various combinations of three additive primary colors, red, green, and blue.
The two other color models that you might be familiar with are CMYK subtractive color (Cyan, Magenta, Yellow, Key-Black) which is used for print and RYB subtractive color (Red, Yellow, Blue) which we are all familiar with from art class.
In the case of RGB additive color: Red+Green = Yellow, Green+Blue=Cyan, Blue+Red=Magenta, Red+Green+Blue=White
The reverse is also true – if you subtract colors by casting a shadow the color of the shadow is a result of the remaining colors.
In photography, we can gel our strobes to produce the exact same effect.
According to Lee Filters, the three gels to use for the RGB primary colors are: Red, Green, Blue (all special order from B&H). Alternatively, you might be able to find these (or similar) included with many of the hot-shoe strobist gel packs.
Photography Inspiration
There some really fun ways to use RGB color theory in photography.
One of my favorites is by photographer Nick Fancher who uses cyan, magenta and yellow gelled hot-shoe strobes to produce a white light on his model with multi-colored background shadows.
And here are two articles by photographer Glenn Norwood for using gels for creating mood and atmosphere with gelled lighting and using gelled lighting for color theory driven stories.
And finally, here are eight lighting setups from Felix Barjou that use colored photography gels for creativity.
Give It A Try And Let Us Know How It Goes!
Have you experimented with different colors of projected light?
What is your favorite application of colored photography gels and additive color theory?
Are you interested in trying this?
Leave a comment below and let us know what you think!
JP Danko
JP Danko is a commercial photographer based in Toronto, Canada. JP can change a lens mid-rappel, swap a memory card while treading water, or use a camel as a light stand.
Join the Discussion
DIYP Comment Policy
Be nice, be on-topic, no personal information or flames.
3 responses to “Fun With Color – Photography Gels and RGB Additive Color”
I never really got the ‘subtractive’ portion of RGB involving shadows…what makes the boys most prominent left hand shadow magenta (and then green to its left)?
I think his left hand is shading the green light – so in the shadow there is only red and blue mixing to make magenta instead of mostly blue and green making cyan (without the shadow). Its a little hard to make sense of though – the lights weren’t set up in a textbook RGB color wheel and they were set up to dim and brighten to change how the colors interact.
Thanks I gotcha! Helped to look at the color without the shadow to see where you started