Blue/Green Screen Portraiture
If you’ve been to a movie in the past few years, you’ve seen examples of blue or green screen photography, even if you were unaware of it at the time. Blue or green screen photography is just one of the techniques that are used to show Transformers stomping LA’s skyline into the dust but each night’s weather forecast includes a meteorologist standing in front of a blue background while an animated map of the country is seamlessly composited behind them.
There are a few basic rules about shooting blue screen portraits but you can feel free to break or ignore most of them if you like because nobody ever said a digital image had to look realistic. The first thing that you will need is a blue or green screen background, like the blur and green background that are ‘s found in Westcott’s Photo Basics Dual 9’x10′ Background kit.
Lighting equipment for blue screen photography is less important than how you light your subject. It’s important to avoid shadows from the person falling onto the background. Shadows on a background are not a good idea for any kind of portrait but can especially be a problem in blue screen portraiture because the shadow could follow the image when it’s composited. That can be a good thing or a bad thing depending on your final image.
It’s a good idea to match the direction of the light in the blue screen portrait with the direction of the light in the background image. That’s the best way to do it when you already have a background image in mind but I realize that may not always be the case. Instead, you may want to play with the lighting in the blue screen portrait to give yourself some options later.
Unless you are shooting for a specific combination of foreground and background images, it’s a good idea to crop the subject a bit looser than you might ordinarily do when making a portrait. Again, it gives you more options.
I like to work with wider apertures to minimize any wrinkles that may be in the background, especially with collapsible blue screens. Any light hitting wrinkles can render them is a slightly different shade of blue (or green.) This doesn’t mean you can’t shoot at what aperture you want. A softer, smoother background just means less postproduction work.
The only unbreakable rule in blue screen portraiture is that the person in your photograph should not wear blue clothing or have anything else on that’s blue. If you want the subject to wear blue, switch to a green background.