How to Make and Use a Green Screen

A Chroma Key video is impossible to make without the most important “ingredient” – a green screen. The cheapest a professional green screen can be is $50 – a reasonable price for an advanced clip-maker, but a little too much for a first-timer. If you’re not ready to invest in professional equipment, simply make your own green screen. A DIY-green screen can be just as good as a professional one if made appropriately.Here is how to make a green screen.

1. Take a large sheet of non-glossy fabric, seamless paper, or other material, and paint it vivid green.
2. When your homemade green screen is ready, either build support stands for it or just hang the backdrop on a wall in your room.

It’s as easy as that! The most important thing you should pay attention to is that the color must be uniform, no matter what you’re using: a poster board, a painted wall, or a sheet.

Now that you have a green background for editing, it’s time to learn a few tricks. Chroma key green screen videos are quite challenging to shoot. Still, the preparatory steps we are to describe are vital and will affect post-production dramatically, so you’ll want to learn how to green screen properly. Here are some tips on how to use a green screen to create a stunning video.

• Adjust the lighting

Lighting is integral to green screen footage, but it’s more than throwing some lights on the set and calling it a day. The Chroma Key technique works because the green screen is consistent and monotone. Adding too much direct light can disrupt the results.

So what’s the best way to light a green screen? With diffused, soft lights. This kind of lighting will eliminate hot spots and shadows, guaranteeing your final product looks smooth and natural – so much so that viewers believe you indeed filmed in outer space! For lighting, try diffusion filters and stick to one consistent type of lamp (fluorescent or tungsten). When lighting from multiple angles, consider buying the same light twice or thrice instead of syncing all light sources. This will help further guarantee a cohesive green screen come editing time. You’ll also want to light the green screen and your actors separately to avoid shadows. Study the background footage you’re swapping in to ensure the lighting on actors naturally mirrors the lighting you’d expect from that type of footage.

• Focus on backdrop details

Setting up your green screen properly is vital. Just like you don’t want the light to disrupt the green monotone, you need to make sure the screen itself is smooth, consistent, and de-wrinkled. Creases or wrinkles can alter the actual color, so it’s best to make sure you invest in smooth, industrial standard green screens for utmost precision. Clamping the green screen in place is also a handy way to keep the backdrop tight and smooth throughout the shoot. A few other things to keep in mind when using a green screen: your actors should avoid wearing green clothing. Anything that’s green in the scene will be removed when using Chroma Key, so opt for different colors unless you’re trying to go for this effect (e.g., for the effect of a head bobbing through the ocean, your subject would want to wear a green turtleneck, pants, gloves, and socks. You could also use a blue screen instead of green, but green is the most popular choice among video producers.

• Set up your camera

The green screen technique doesn’t actually involve your digital camera – you shoot with the green screen then key it out in post-production – but that doesn’t mean you should hit record and see what happens. Here are a few filming strategies to keep in mind. Exposure: Since you have lighting already, keep your ISO low to avoid noisy and overly grainy footage. Make sure the footage is bright enough to fit with the backdrop seamlessly. That’s where a quick test run can do wonders for the final look of your film. Settings: Use an aperture of f/4 to f/5.6 to add a slight blur that smooths out your screen. Also, go for a shutter speed of about 1/80 or 1/100. This will minimize your motion blur. Focal length: To ensure cohesiveness, match the focal length of the green screen footage and final background footage as possible. If you’re using stock footage, study the settings beforehand, then set up your green-screen scene to match it. Quality: Film with the highest quality format your camera offers. It doesn’t matter if it’s a DSLR, smartphone, mirrorless camera, or camcorder; as long as you have at least 1080p, you’re all set – although 4K footage is even better.

• Plan the general production setup

Keep your actors at least three to six feet from the green screen to avoid shadows. Also, think about the backdrop you’re swapping in. What makes sense for your subjects’ actions? Should they look one way versus another or walk in a particular direction (e.g., toward the mountain versus away from it?) Also, don’t forget a sturdy tripod. With any film, you want the footage to be as steady and shake-free as possible – and that’s even more important when you’re fusing one video with another. Shaky subjects with a smooth and steady desert background will look glaringly off to the viewers.