Ever wonder how a photographer could have possibly gotten their model on to the space shuttle floating around Mars, or a diver surrounded by sharks? They probably used a green screen! A green screen is a technique originally developed by the film industry to allow a subject to be transported into any location imaginable (digitally, of course). A green screen is, quite literally, a large green sheet in front of which a subject is photographed so that the background can be removed and changed in the editing process.
However, unfortunately using a green screen in photography isn’t as simple as painting a wall green and plopping a person in front of it. Effective green screen photography requires great lighting and a good grasp of editing software!
Why Green for a Green Screen?
Before we get to the technical stuff, let’s answer the question on everyone’s mind: why green?
Really, there is no fancy technical answer. Green is just the color that is less likely to be seen in skin tones, and stands out the most from everything around it (except, of course, if you’re wearing a green shirt). You can do ‘green screen’ photography with a variety of colors, from blue to purple. Green just tends to be the safest option for the majority of circumstances.
Does a Green Screen Have To Be a Screen?
Nope! A green screen can be made of a variety of materials. Some use photography backdrop paper in a bright green color, others use fabric, and some paint the wall green. Anything that has a solid green color can work just fine.
How to Best Light Up a Green Screen
The secret to using a green screen in your photography is lighting. A green screen is only effective if it clearly stands out from your subject. As such, the screen itself needs to be lit independently from your model.
Take two lights and place them on either side of the green screen, angled towards the green screen. It’s best to use a softbox so that the light spreads evenly. Experiment with the light distance to find the sweet spot in which the entire green screen is lit up in one tone, no super light spots or super dark spots. Making sure the green screen is one tone is super important.
Next, you have to light your subject. Experiment with lighting to ensure that the subject’s shadow is not falling on to the green screen. Make sure the light is pointed away from the green screen and hits only your subject!
It’s a good idea to take sample shots during the lighting set up to make sure everyone is illuminated the way you want it to be.
Tips for Green Screen Photography
After you’ve gotten the lighting down, here are some tips to keep in mind when photographing using a green screen!
Tip 1: Get the Wrinkles Out
Remember how we have to make sure everything is even? Wrinkles make this hard! Make sure that whatever you are using as a green screen is free of wrinkles. For fabric, you can get rid of wrinkles by spraying it with water or a handheld steamer. Try to stretch it tight as it dries to reduce the lines that may cause shadows in your background.
Tip 2: Avoid Light Spill
Light spill is when light from the background or foreground reflects onto your subject. In the case of green screens, this causes your subject to potentially have green tints. As we are removing all of the green in an image, we want to avoid this as much as possible!
The first, and easiest thing, you can try to avoid the green light bouncing back is to simply move your subject as far in front of the background as possible. The further away the subject is, the less light will bounce back!
Next, if you are able to, avoid lighting your subject from the front. This is because when you use lighting from the front, it will hit your background, then bounce back towards your subject. Try to light your subject at an angle from either side.
Tip 3: Make Sure Every Part of the Model is On the Green Screen
This is where being attentive is key. Make sure every part of your subject is in front of the green screen when capturing an image! A small bit out of frame can make editing a challenge.
Tip 4: Make Sure the Lighting Matches the New Background
The effectiveness of green screen relies on believability. As such, pre-planning what you want to do is a great idea prior to setting up the green screen and placing a model or object in front of it.
Be sure to study the direction of the light in the digital background you have selected for your new backdrop, and mimic the natural way light would fall on your subject. Matching the intensity of light will also help make your composite photograph look much more realistic.
For example, if you picked a bright noon day, make sure your light is directly above the subject. If you picked a day that is overcast, soften the light you use significantly. If light is creeping from the left side, make sure the subject’s left is brightly lit and the rest is darker.
Tip 5: Use Chroma Key Software
Chroma key is a term you will hear very often associated with green screens. Chroma keying is the actual technique of compositing two images based on color hues. Every color has a chroma range, and that is where the term comes from.
There is software available, including in Adobe Photoshop itself, that can locate the green and remove it using Chroma Keying. This is your absolute best bet to very quickly extract the green screen and replace it with the backdrop of your choice! Otherwise, you can use various selection tools in programs to do the same thing, but Chroma Key tends to be the most accurate.
In conclusion, being versed in how to use a green screen can be a big bonus to any photography business, allowing a variety of backdrops to be used for your clients!