Let’s look at the image above for a minute. Look at the light. Study the complexity of color for a few minutes. What do you notice?
Clearly this image was shot in a studio with strobes, but, would you say it totally looks like it was lit with strobes? Why does it look this way?
Lets break it apart a bit and see how we got here.
We’ll start with a simple truth: White light is a lie. Since when does white light occur in nature? It doesn’t. What we call white isn’t actually all that white, it’s largely just a way for us provide a point of reference to describe other colors of light.
Would you believe me if I told you that the above photo was actually lit with 3 different strobes and they where all different colors of light?
It’s true. Let’s walk through it.
The key light is to camera left. It’s a pretty standard 45 degrees over and 45 degrees up. It’s a Paul Buff X1600 White Lightning strobe in a LumoPro 36 inch Octo-box. Nothing special there. Where it starts to get interesting though is that it is gelled so that the color it emits is red. Specifically, 15 units of Rosco CalColor Red.
Wait. What? Why isn’t everything red then? Well, if that was the only light being used, it would be, however, we’re mixing colors, so lets look at the other two lights.
The primary fill light is another Paul Buff X1600 White Lightning. I’ve put a 180 degree reflector on it and pointed it at the giant white wall behind the camera. I then gelled it with 90 units of CalColor Green, and 60 units of CalColor Blue. This results in a really greenish bluish color if used alone, and because of its position, it basically fills every crack and crevice with this light.
There is a secondary fill light in the form of a LumoPro LP180 speed light pointing at the white wall to the camera’s right and it is gelled with 90 units of CalColor Blue.
Where the magic comes in is how all the lights mix together, because what we’re doing is mixing colors to get a resultant color. Even though all the strobes were metered at different levels, combined with the various gel strengths (this is the reason I use Rosco CalColor gels, they’re calibrated and it’s fairly easy to figure out how much you need for a given light level) in RGB terms, the resulting color is basically 255 red, 170 green, 85 blue. If you plug that into pretty much any RGB color calculator online what you’ll end up with is what looks like about a 1/2 CTO gel.
So why not just do that? Put a 1/2 CTO gel on all the lights. You can, but it wouldn’t look all that interesting.
This is where the chromatic complexity comes in. Each color is coming from a different angle and hitting the subject at a different angle. Where all three colors are hitting the subject, you get the effect of having a CTO gel, however, in the areas where only two or one of the lights is hitting the subject, the color of the light is dramatically different.
Take a close look at the shadow side of the subject’s face. It is most definitely pushing to blue. It’s subtle, but it’s there. The shadow side is lit so that it’s 3 stops down from the key side, so even though the strength of the gels is pretty high, the effect is actually very subtle.
Now, this is how I think about light and how I light. There are many ways to Rome. You can accomplish something very similar by actually just putting a 1/2 or full CTO on the key light and a full CTB and 1/2 plus green on the fill, and in fact, a lot of very experienced photographers do just that and get more than acceptable results. I prefer the CalColor gels because it allows me to be quite a bit more precise, and that’s just how I roll.