Personal computers, ubiquitous smartphone video cameras, and video upload services like YouTube have put once prohibitively expensive/technical filmmaking tools into virtually everyone’s hands. This includes the use of software that replaces complicated production processes. Green screening, an effect that once required elaborate processing, is now bundled in green screen software packages that allow anyone to try it on their laptop. All you need is a green backdrop, a camera, and a laptop.
What Is Green Screen?
Green screening, known technically as chroma key compositing, is a video production process commonly used to place an image of an individual filmed in front of a green or blue screen onto a background image filmed separately. When done correctly, it can appear as though the individual actually appeared in the background image.
The green or blue backgrounds are used because those colors do not appear in the natural human color palette, which makes it easier to eliminate the background without affecting the performer’s image. One challenge to this special effect is that no part of the performer’s wardrobe can be the same color as the green screen, as it would be cropped out along with the background.
The most familiar use is the popular local television news weather report format, which places the weather reporter in front of digitally created weather maps. In the studio, the reporter is actually in front of a green backdrop, and the map is married to the background instantaneously. To see where she is gesturing on the map, the reporter watches the combined image on a television monitor placed just off camera.
Increasingly advanced green screen software has allowed more elaborate major-budget films. This allows actors to act out the script on a green soundstage, then be superimposed into settings that would be too expensive, too dangerous, or too fictional to film for real.
12 Green Screen Tricks That Will Up Your Game
1. Soft Lighting Is The Key To Your Success
Regardless of camera quality, background color choice, or green screen software, the proper subject lighting is the single aspect that makes or breaks your green screen effects. First, the more even your lighting, the more single-color your background appears to the computer, and the easier it will be to make it disappear. Choose softer, rather than sharp, lighting to achieve this. Avoid putting lights directly on your subject.
Better (and more expensive) equipment makes all things easier and faster. However, your budget will dictate what equipment you have access to. If you are more of a basement production, inexpensive hardware store painter’s lights can be used to great effect. There are professional filters and tools for diffusing your light, but experimenting with thin white paper or fabric can emulate this on a budget (be cautious of interactions between flammable materials and hot light bulbs).
2. The Three Things You Must Light
Now that you are working with soft lighting, there are three main things to light on your set:
- The background, which needs to be lit as evenly as possible. For best results, use several lights from different angles, high and low.
- The actor who needs to be lit from behind at a high angle. This serves to help visually differentiate the actor from the background. On a budget, ceiling light with a diffused lamp shade can serve this purpose.
- The “key” or main light and “fill” light, which light the actor’s front. The key light focuses on the actor, to create contrast, particularly in their face. A fill light on the opposite side will help eliminate drastic shadows.
3. Green Screen Is Preferable To Blue
Actors with blue eyes can cause issues when you crop out blue backgrounds.
4. Try Different Shades Of Screen
Sometimes the shade of green or blue you are using as a background can cause issues with a particular shot. Check your hardware store or fabric store and see if you can locate a different shade and conduct some test shots using it. Many hardware stores sell chroma key specific paints. You can also price-shop online.
5. Your Screen Surface Needs To Be As Even As Possible
The green background can be paper, fabric, or even a painted wall. However, it must be as smooth as possible. Wrinkled or textured backgrounds create shadows and lines with enough contrast to complicate your background elimination efforts.
6. Do Early Test Shots With Your Talent In Wardrobe
Even if you are careful choosing fabrics and accessories, some surprises can appear. Some clothing uses blue and green threads that may not be readily apparent until you see it on screen. Additionally, reflective fabrics, buttons, sparkly jewelry and other surfaces that pick up a green or blue hue from your background can cause issues with your green screen software. Eyeglasses also present a special challenge. Are they necessary? Can they be replaced with less-reflective lenses?
7. We Need To Talk About Your Hair, Blondie
During test shots, watch the talent’s hair. Blonde is challenging as it can pick up a green hue from your background. One trick is to light hair from the back with a magenta light or filter. Because magenta is the opposite of green (we are talking color wheels here), it can offset the green hue issue.
Unfortunately, the same green colors that create magic for our background images can make talent appear pale and sickly. This is where makeup can help rescue the magic.
9. Keep A Cushion between Talent And Screen
By cushion, we mean distance. If your talent is too close to the screen, it may cause shadows on the screen and green hue on the talent. Both present challenges you want to avoid having to deal with in your green screen software. Experiment during test shots with how far talent needs to stay in front of the screen. Mark this on the floor so that talent can return to the same spot.
10. Keep Your Talent In A Box
Your green background will define the frame in which your actor can move. One solution is to make the green background as wide as possible, but that is not always an option, particularly when working in the field rather than the studio. During test shots, work with the actor to ensure that they know how to stay within that frame. A stray gesture, wandering too far, or a drifting bit of wardrobe moving outside of the green background destroys the illusion you are trying to create with this effect. No amount of green screen software magic can fix it. Mark these limits on the floor so that talent can see it while performing.
11. Try Different Shots
With all the limitations on lighting, space, and movement, we have virtually jailed our talent. However, you have editing on your side. Rather than try to get all the talent’s efforts into a single shot, which may complicate your efforts, break out the shots you need to tell your story. Try additional shots focused just on the talent’s face, limbs, or even parts of the wardrobe. Close-in, controlled shots can help you ease issues caused by trying to get it all at once. If a gesture keeps going “outside the box,” moving the talent to the center of your stage, then framing just the arm/hand making that gesture can keep it in the box, and add image variety, even intimacy, to your edited piece.
12. Experiment With Different Green Screen Software Packages
Thanks to free-trial software, we have the luxury of trying out different video effects packages to see if their green screen software suits our needs. Many major editing packages include it, but you are not required to lock yourself in there. There are stand-alone green screen software packages and smartphone apps that give you more flexibility than the big guns.
Top Green Screen Software Tutorials
Green Screen Video Editing Tutorial - YouTube
PhotoKey Green Screen Software Tutorial - YouTube
How To Make Chroma Key - Green Screen Effect? - YouTube
How To Use Green Screen In Movavi Video Editor - YouTube
Green Screen Tutorial - The RING Effect (Come Out from TVs) - YouTube
Regardless of your budget or expertise, the elements of green screen are easily accessible. Whether you run a major production house or seek to bootstrap your way from basement studio to YouTube fame, the basics are the same. A green background, some lighting technique, green screen software, a little know-how, and (especially) experimentation will reward your efforts with some of the same special effects that put the Death Star in space, let Gandolf battle demons while tumbling through the Middle Earth, and help your local weather reporter look like she has her own fleet of satellites.