DIY Photography with Larry Becker: Gels
Option Two: Gels
If you’re going to the trouble of gelling a light, you might as well do it with accurate colors. A pro might buy orange or blue gels from a camera vendor (such as B&H), and the key is to buy it in large sheets rather than custom-cut for your flash head.
The most common kinds of gel are referred to as CTO and CTB (color temperature orange and blue, respectively), and then the density—how orange is the orange?—is referred to as a fraction of a “cut.” In other words, adding just a little orange tint to a flash could be done with a 1/4-cut CTO gel. More orange would be a 1/2-cut or full-cut CTO. (I found sheets of 1/8-cut to a full-cut for around $6 for a 20×24″ sheet.) Then, all you have to do is cut the proper shape with scissors and you can get dozens and dozens of gels from a single sheet.
Here are a couple of hints. You don’t need to buy all of the increments of plastic gels because with most flash photography, a 1/8-cut doesn’t make sufficient change to be worth using, so ignore it. A 1/4- to a 1/2-cut is what photographers will use most of the time. But here’s the cool thing: You can stack these little pieces of plastic so that two pieces of 1/4-cut CTO is the same as one piece of 1/2-cut CTO. I own four flashes, and one sheet of
1/2-cut CTO and one sheet of 1/4-cut CTO is more than enough to have all that I need for all four strobes.
The added benefits to professional-quality gels are that they’re accurate in color and they’re also heat-resistant, making them less likely to melt.