The short version
- Light the backdrop evenly, separately from yourself.
- Stand at least 1.5–2 metres (5–6 feet) in front of the screen to avoid shadows and green reflections.
- Don't wear green, or anything shiny or very fine-patterned.
- Lock your camera's exposure, focus and white balance.
- When keying, sample the actual backdrop colour rather than assuming pure green.
How chroma keying works
Chroma keying removes every pixel that's close to a chosen colour (the "key") and makes it transparent, so whatever is underneath shows through. Good keyers compare the hue of each pixel with the key colour, not just its brightness. That's why an evenly coloured backdrop matters more than a perfectly bright one: a screen that goes from bright green to dark green is harder to separate from your subject than one that's the same shade all over.
Why green (and when to use blue)?
Green is the most common choice because it's far from human skin tones, and digital camera sensors capture green with the most detail, which gives cleaner edges. It's also bright, so it needs less light.
Use a blue screen when your subject contains green — plants, a green shirt, green eyes in a tight close-up — or when green spill (see below) is a constant problem. Blue reflects less light onto the subject, but it needs more light to look even.
Choosing a backdrop
You don't need a studio. Any of these can work well:
- Fabric backdrops — cheap and portable. Choose a thick, matt fabric and stretch it tight or steam out the creases: wrinkles make shadows, and shadows are harder to key.
- Collapsible pop-up screens — quick to set up, naturally taut, and good for head-and-shoulders shots.
- Seamless paper rolls — very even and matt, but they tear and scuff.
- Painted walls — chroma key paint on a smooth wall gives the most even surface of all if you have a permanent space.
Make it bigger than you think you need. The screen must cover everything behind your subject for the whole shot, including when you gesture or lean.
Lighting: the most important part
Most keying problems are lighting problems. The goal is two separate jobs done by separate lights:
- Light the screen evenly. Use two soft lights, one on each side, aimed at the backdrop from about 45°. Walk your phone across the screen with the camera app open: if one area looks noticeably darker or brighter, adjust until it's uniform. Avoid hot spots and fall-off at the edges.
- Light the subject separately. Use a key light in front of you (a large window works) and, if possible, a light from behind and above — a "rim" or "hair" light. The rim light makes a thin bright outline around your hair and shoulders, which separates you from the background and suppresses green reflections.
Distance and spill
Spill is green light reflected from the screen onto your subject — a greenish tint on hair, shoulders, skin and glasses. When you key, those areas become semi-transparent or keep a sickly green edge.
The best cure is distance. Standing 1.5–2 metres (5–6 feet) or more in front of the screen:
- stops your shadow landing on the backdrop,
- reduces the green light bouncing onto you, and
- lets you light yourself and the screen independently.
Whatever spill remains can be reduced in editing with a spill-suppression control, which removes the green tint from the edges of your subject.
What to wear (and avoid)
- No green — or blue on a blue screen. Anything similar to the backdrop will disappear.
- No shiny or reflective items: sequins, glossy fabric, polished jewellery and glasses reflect the screen.
- No very fine patterns or wispy textures such as fine stripes, mesh or fluffy jumpers. Fine detail blurs into the background when keyed.
- Tie back flyaway hair if you can. Individual strands are the hardest thing to key cleanly.
Camera settings
- Lock exposure, focus and white balance. If the camera adjusts during the shot, the screen changes colour and brightness and the key changes with it. On most phones, tap and hold on your face to lock focus and exposure.
- Avoid motion blur. Blurry edges on moving hands are part-green and part-you, so they key badly. More light lets the camera use a faster shutter.
- Record at the highest quality you can. Heavy compression creates blocky colour noise around edges. Higher resolution and bit rate help the keyer.
- Focus on the subject, not the screen. A slightly soft backdrop is fine — even helpful, because creases and fabric texture become less visible.
Step by step: remove a green screen in VDOAPP
In our free online editor, a green screen clip goes on top of the background as a picture-in-picture overlay.
- Add the background first. Open the editor and add the video or photo you want behind you. This is your main clip.
- Add the green screen clip as an overlay. Open the PiP tab and choose + Add video or photo overlay. Pick your green screen footage.
- Size and place it. Drag the overlay's pink corner handle to make it bigger — up to full frame — and drag it into position.
- Turn on Chroma key. Tick Chroma key. The default is the standard chroma-key green, which works on many screens straight away.
- Sample the real colour. Press 🎯 Pick from video and click on the backdrop in the preview. It averages a small patch, so noise doesn't throw it off.
- Fine-tune. Raise Strength until the whole backdrop disappears; if holes appear in your subject, lower it. Increase Edge softness for smoother edges, and Spill cleanup to remove the green tint from hair and shoulders.
- Check a few moments by scrubbing through the timeline — especially frames with fast movement — then export.
Troubleshooting
| Problem | Likely cause | Fix |
|---|---|---|
| Patches of backdrop remain | Uneven lighting or creases | Raise Strength a little; re-pick the colour from the darker patch. Next time, light the screen more evenly. |
| Holes in the subject | Strength too high, or green in clothing | Lower Strength. Avoid green clothes, or use a blue screen. |
| Green outline around the subject | Spill | Increase Spill cleanup. Next time, stand further from the screen and add a rim light. |
| Hard, jagged edges | Compression or low resolution | Increase Edge softness slightly; record at higher quality. |
| Hands blur into the background | Motion blur | Add light so the camera can use a faster shutter; move a little slower. |
| Result looks "pasted on" | Lighting doesn't match the background | Pick a background with similar light direction and colour, or apply a filter to the overlay to match. |
Making the composite believable
- Match the light. If the sun in your background comes from the left, light yourself from the left.
- Match the colour. Use a filter or brightness and contrast adjustments on the overlay so its tones sit naturally in the scene.
- Match the perspective. Film at roughly the same camera height and angle as the background was shot.
- Mind the edges of frame. If your feet or the bottom of your body aren't in shot, crop the overlay so it ends at the frame edge rather than floating in space.