Jason Lenhart Photo Blog: Color Correction

Another assignment, right on the back of the single flash one, and just as tricky. In this assignment we learned to balance the color of lights when we use flash. I'll explain. All lights (yes, ALL) have different color temperatures. We don't usually notice, because our brains are adept to adjusting to that. We see something white, and under most circumstances, we recognize it as white. But have you ever been in a room that is just lit really weird, with bad lights, and you can recognize that everything is "kinda orange" or "a little green"? Well, our cameras always see the color that way. It is up to us to adjust for these different color lights using White Balance. White balance basically tells the camera "This is white" and makes it adjust accordingly. We have presets on the camera that will adjust to incandescent, fluorescent, daylight, shade, flash, cloudy, and sometimes more. Many cameras also have an AUTO and Custom (or PRE). In this assignment we focus on the Custom White balance because we are dealing with two lights.

When you bring flash into the scenario, most flashes are daylight balanced, and therefore the "flash" or "daylight" white balance would suffice. But what if you are shooting flash in a room lit by ugly green fluorescents? If you pop flash under the daylight white balance, the subject flashed will be correct colors, but anything lit by the fluorescents, like the background, will be green. We can fix this by using gels on our flashes. A gel is a thin, color piece of transparency that goes over the light, making it that color. So when we are shooting flash in a fluorescent room, we put a green gel over the flash to make all the lights in our photo relatively the same color. That way, in the camera, we can do a custom white balance and EVERYTHING (in theory) should be correctly balanced. Make sense? Well, it's a bit more simple that the actual practice of it. Many lights, especially now with CFLs, are not what we perceive. Fluorescents could be warmer and therefore balanced more like an incandescent. Sometimes they are still the same color, but a warmer or cooler, so a warmer or cooler shade of gel would be required to make it perfect. Getting it perfect is very tricky, but getting all the lights the same color to the best of your immediate ability, is better than nothing. The following photos are two examples. The first shot is made under fluorescents with the daylight balance and no flash. Ugly. The second is made with flash, but the flash is not gelled. Finally, The third is shot under the same fluorescents. While still green under daylight balance, a lighter green gel should have been used, rather than the darker that I used. If you look on the wall behind the girl, you can see the lights on the wall are a semi-pink. They are not balanced perfectly, but better than the previous two shots, no?

Photo © Jason Lenhart

Notice the terrible green tone. This is what fluorescent looks to our cameras.

Photo © Jason Lenhart

Now, in this one, some items in the photo appear to be white. This is flash under daylight. Since many flashes are balanced for daylight, the camera is OK with this. If you look at the background, you can still pick up the green tint. This is from the Fluorescents.

Photo © Jason Lenhart

Here we have the green gel and a custom white balance. Everything, for the most part, looks in balance. You can see the slight pink tones in the background near the lights. I'm not absolutely sure why that happens, but it may be that my gel was too powerful for these lights. Overall, its a much better photo that the other two.

These next two are the before and afters. They are balanced using orange gels under fluorescents acting as incandescent.