Photoshop Compositing Secrets - Matt Kloskowski [14]
STEP TWO:
Now, just paint on the layer along the edges of the hair that are too dark. Each brush stroke will lighten them, since you’re only using 10% exposure (it’s like opacity). The same thing applies to darker hair with white fringes around it. The only difference is that you’ll use the Burn tool instead. It’s nested beneath the Dodge tool in the Toolbox (or just press Shift-O until you have it). Use the same settings, though.
The Best Background Color for Selecting & Extracting
There has been a lot of debate about what the best color is to photograph a person on so they’re easy to extract in Photoshop. Let’s put this one to rest and take a look at all of them (white, gray, black, and green). You’ll find that, as long as there’s a good amount of contrast between your subject and the background, just about anything will work. In fact, later in the book, you’ll see we don’t have real studio backdrops behind some of the people we’re working with. But, if you’re in a controlled environment (like a studio), when it comes to shooting specifically for compositing and extraction, there’s one color that just makes the most sense.
GRAY:
Let’s start with my favorite choice, gray. Actually, light gray. Here’s a photo of a woman on a white seamless backdrop that has no light aiming at it. The lighting setup is similar to one I wrote about in “10 Things You Need to Know About Compositing”—one light in front and one light on the side to get that nice edge/accent light on her body, face, and hair. Because there’s no light pointing at the background, it falls to a light gray. For me, and the selection tools I work with, light gray seems to work best. Once in a while, if the subject happens to be wearing gray, it can miss a few edges, but it’s always a quick, easy fix. For hair and detailed edges (the hardest part about selecting), gray seems to do the best job.
WHITE:
Here’s a photo of the same woman taken on the same white seamless backdrop, but here it has been lit. In the studio, to keep the background white, you need to point a light at it. If you take a photo of it with no light aimed toward it, the background turns a light (or dark) shade of gray, depending on what other lights are pointed toward it, and how far away the entire setup is from it. White actually works really well for extracting. In fact, I’ve found it’s one of the best colors for Refine Edge to work with. Here are the problems, though:
When we point a light directly at the white background, some of that light inevitably reflects back to the subject and causes a bright light to wash over the edges of their body and clothing. If you’re placing them onto a brightly colored background, it’s not a huge problem. But, if you’re putting them on a darker background, it won’t look right. It’s hard to describe, but when you see it, there’s just something that looks off, because there’s so much bright light around them.
The other problem with the all white background is that we’re using one or two edge lights (check out “10 Things You Need to Know About Compositing” for more on lighting). These lights make the edges of the subject’s clothing and skin almost white. Not all-white mind you, but close enough to confuse Refine Edge and make selecting the hair and body a pain.
BLACK:
Here’s another photo of the same subject and the same lighting setup we saw with the gray backdrop, but this time we’re using a black backdrop. With no light pointing directly at the background (our main light will cast some light on it), the black stays mostly black. The problem with black is that dark clothes (which are pretty common) don’t give Photoshop enough contrast to select with. Even worse, someone with dark hair really presents a big problem. You have to make sure you light all of the hair to give enough separation for the selection tools to work. Otherwise,