Working with a Green Screen Is Easier than Ever — Here’s Why
In recent years, working with a green screen has changed. Take a look at a few new factors that have made the process easier than ever.
When I was directing TV commercials ten years ago, green screen was a much-used-but-incredibly-painful, process. Green screens were made of plastic, they were very shiny, and they would often develop creases. The only option was to light them with tungsten or fluorescent light, which spilled green everywhere and clashed with skin tones. Once you got footage into post-production, you had to overlay multiple different keyers, with different ranges, as well as use garbage mattes to finesse the shot. You did all this difficult work to get something usable, and you usually had to manually rotoscope out things that went wrong. It was hard, finicky work, and it wasn’t something you looked forward to doing.
1. Start with the Right Green
If you’re going to shoot outside and you don’t have control over the brightness, start with the right material, and get a proper chroma key green. If you’re shooting inside, get a digi green, which will give you a nice, clean green. If you have RGB-capable LEDs and can light with green, you’ll get the right exposure with much less brightness, and as a result, have less spill.
2. Separate from Your Subject
It’s important to have your green screen and your subject at least six feet away from one another, so you’re not contaminating your subject with spill from the green. You also want to light them separately (i.e. you want to light the green screen with green and your talent however you desire, but ensure that there is a clean separation between the two).
3. Raw Is King
Shoot in at least 422, but most probably raw. Raw has a whole separate channel for the green screen, so you can avoid color contamination, or chroma sub-sampling that will mess up the edges of your key.
4. Expose the Background Properly
You need a 30-40 percent brightness green screen for a clean key. The easiest way is to see a consistent line across your waveform — if your camera is capable of displaying one. You should do this even if your subject is dark. Light the background and foreground separately.
5. Eliminate Motion Blur
You also want your shutter speed above 1/100 or 90 degrees if you’re using that measurement. This reduces motion blur and stops the green from being dragged into the blurred elements of your main subject. If you’re not aiming for that Saving Private Ryan staccato motion, you can add motion blur back in post, but it’s going to be a lot easier once you’ve keyed your subject.
6. Let the Software Do the Work
New keying software, like the Delta Keyer in DaVinci Resolve, can give you a single-click key because they use artificial intelligence to analyze your image and make educated guesses about the right settings. You really can have a “one-click” key if everything else is exposed correctly.
This took only five minutes to get a beautifully keyed-out background. You can do green screen almost as easily as you can color grade your footage, so absolutely experiment with it! See how you can push back the limits of storytelling, expand the world you’re creating, and generally push your filmmaking to a whole new level.
Looking for more video tutorials? Check these out.
- Stabilizing GoPro Footage with the Unique ReelSteady GO App
- Quality vs. Quantity: What Should You Record While Traveling?
- Editing Tips: Sorting Footage and Creating Quality Timelines
- From The Wizard of Oz to Transformers: 100 Years of Color Grading
- Creative Uses for Bokeh Overlays + Free Prism Bokeh Pack