Green screening allows even the smallest video producers to create amazing content with impressive effects. But, green screening can be challenging - get it wrong, and you can blow it with your client. Even if you are able to save a bad chroma key shoot, it may take hours of frustrating work to fix your final product.
There are a few things you need to know before you attempt to set up your own green screen studio or take green screening on location. Gustav Wilde of Cogito Creative spoke to members of the Atlanta Internet Video Marketing Association on how to set up a professional green screen. Here are his 6 top tips for video creators:
Green Screen Tip #1: It’s All About the Lighting
Proper lighting is absolutely crucial when it comes to achieving a professional look. The most important thing about green screening is the lighting, you must have proper lighting to make the green nice and smooth. You have to have one color so, when you pick that color, you don’t have to do multiple chroma keys - you can just pick one spot on there and that whole background is just gonna disappear. Your editors are gonna thank you, and you’ll get the final product a lot sooner.
While you might think an expensive camera or the right software is just as important, even the best camera and editing program won’t fix bad lighting. The lighting must be even so that the background is all the same color. When your lighting is soft and even, it’s much easier to use just about any software, including I-Movie, to remove the background and have it become transparent.
Background Lights, Key Lights, and Fill Lights
Gustav uses five to six lights to set up a green screen on location. Two or three lights are used to light the background. He advises lighting the background first and making sure the light is evenly distributed. Once the background is right, he begins lighting the actor. The first step is adding a backlight. The backlight is used to light the actor from behind. It’s placed overhead shining down on the actors shoulders and hair. It’s sometimes called a hair light. The backlight is there to separate the actor from the background. “Be sure to diffuse the backlight so that it doesn’t look like a white halo around the person,” Gustav advised.
The next step is setting up a key light - your main light - the one which is focused on the actor’s face and body. The key light should be diffused giving a soft and even look. The next light also goes on the actor, and it’s what’s called a fill light. It fills in on the opposite side of the actor. The key and fill together create a small amount of contrast on the face, designed to show more interest than even light across the face. Gustav says that you can use a large diffuser like he demonstrated on his key light and an umbrella on the fill light or you can use softboxes. “You want the lighting to be even. You don’t want light green and dark green".
Gustav uses and highly recommends Omni lights and Tota lights. But, he also showed the audience that he still keeps Home Depot painter’s lights in his stash, just in case it’s a “run and gun” type of shoot. He says that if you’re just starting off and on a budget, these types of lights will work, but you’ll spend more time trying to get the lighting even.
Green Screen Tip #2: Choose Your Surface Wisely
Chroma key screens can be blue or green, so you would want either a green or blue background. Green is used more often than blue because blue eyes can actually key out, looking a bit strange. These colors are used in chroma keying because they are not present in any skin tones, no matter the ethnicity. When you remove all the green or blue, the actor will show up just fine, as long as they aren’t wearing green or blue.
Gustav mentioned several types of surfaces which you can use for green screening. He says that no matter what you use, paper, a painted wall, or fabric, you are looking for a smooth appearance. A wrinkled cloth or reflective paper won’t work. You want a smooth, even look, just like you want for the lighting.
Gustav’s favorite selection for green screening in a studio is a painted wall. Obviously, that won’t work on location. “The best one (surface) is a painted wall. Some have a sloped floor as well. We use paper a lot - it’s easy to set up on location. You can use cloth - but it’s hard to keep it smooth,” Gustav said.
Foam is another possible background. There are also small portable cloth green screens which “pop out” when you unfold them. “Pro Key” is also an expensive, but effective method, which uses a grey cloth with green reflections in it. You must also use a green light to reflect the cloth. With this type of green screening, there is a need for additional software.
Green Screen Tip #3: Watch for Movement
Gustav mentioned one of the biggest challenges with green screening is that you have to make sure your actor doesn’t move any body part outside of the green background. One hand gesture reaching just outside the green area can ruin your entire shoot. There really is no way to fix a missing hand in post-production. The only thing you can do is to cover up that shot. Gustav advised having your actor move around before you start shooting, making sure there aren’t going to be gestures outside the green screen background.
Green Screen Tip #4: Watch Reflections and Challenging Hair
Even if your lighting and background are great, blonde hair and thin fly away hair can be challenging. The color, yellow, is close to green. So, keying it can be difficult. Gustav says that if the actor has blonde hair, you might want to use a magenta gel on your backlight, which will counteract the green. “It’s the opposite color on the color wheel”, Gustav said.
Other challenges include reflections. Watch eyeglasses and reflective jewelry. Anything that sparkles or reflects will be challenging to key. It’s much easier to watch for and remove those objects before you start shooting than to deal with them in post production.
Green Screen Tip #5: Watch For Shadows
Shadows can be a big challenge when green screening. “You don’t want your actor too close to the screen. You want to be 8 to 10 feet out from the green screen to avoid shadows”, Gustav advised. If you do end up with a darker green caused by shadows, Gustav says you may have to do a couple of different chroma keys in order to fix the problem.
Green Screen Tip #6: Choose The Right Software
Final Cut Pro, Adobe Illustrator, Adobe Premiere and even I-Movie can all be used to green screen. Gustav uses Adobe Illustrator most often but when asked about I-Movie, Gustav said, “It’s amazing”. I-Movie is a free software on Macs. So, it’s a great way to get started.
Gustav was also asked about what videographers should expect to spend when setting up a green screen studio. He said the price can vary greatly. But, if you want really professional lighting, “It’s going to be around $800”. Of course, that does not include the price of the camera.
While setting up a studio in your home could be as simple as investing in paint, painter’s lights, a camera, and a program like I-Movie, Gustav advised that it all comes down to time versus money. The painter’s lights are more challenging. But, you can take plenty of time to set them up in your studio. When it comes to location green screening, you have to consider your time in every shoot. You certainly wouldn’t want to take three hours, and you don’t want to spend additional time correcting all the problems in post production.
You can see an edited version of Gustav Wilde’s presentation below:
So, with these tips and a little trial and error, you can start green screening right away. Just remember, invest either time or money in getting the proper lighting and the proper background. These two elements are the “keys” to great “keying”.