What do you need for a green screen shoot?

A green screen looks simple: green background, swap it later, done. Anyone who has done one knows that you only find out in the edit how well you worked on set. Green fringes around hair, a shadow on the floor you cannot get rid of, a shirt with a green print that suddenly turns see-through. Almost all of that is fixed on the shoot day, not after it.

How much green do you need?

It depends on what is in frame. For a presenter framed from the chest up, a green wall behind them is enough. If you want someone walking head to toe, you need a green floor and a cyc (limbo) that joins wall and floor without a seam.

Be generous. Your subject needs to stand a few metres from the background, otherwise green light bounces onto skin and clothes (spill). And your camera needs enough room to pull back and frame the whole body without leaving the green.

Some sizes from the site for comparison. Green Screen Studio Utrecht has a green cyc and floor 8 metres wide, 9 metres deep and 2.9 metres high. Studio2Go in Haarlem has a small green screen studio of 38 m² and a large one of 120 m², both 4.8 metres high. Mirage3D in The Hague, at 200 m² with a green screen of 13.5 by 14.8 by 11.5 metres, is one of the largest. If people jump, dance or you bring in a car, ceiling height matters as much as floor space. See also what size studio you need.

How do you light a green screen?

The core principle: light the background and your subject separately.

The background should be as even as possible. No hotspots, no dark corners. The more even the green, the easier and cleaner the key. Some studios come pre-lit. According to its studio page, Mirage3D includes 92 tablet-controlled LED panels in the ceiling plus extra floor panels in the base rental. Green Screen Studio Utrecht and Studio2Go say the studio is lit as standard. That saves you half a day of setup.

Then light your subject the way the scene you will place them in is lit. If the sun in your background comes from the left, bring your key from the left too. A backlight or rim light helps separate the person from the green and reduces spill on the edges.

More on setups in lighting setups in a rented studio.

Clothes and props

• Nothing green. No green print, green soles or green logo either.
• Watch out for reflective and shiny things: glasses, jewellery, glossy fabric. They pick up the green.
• Fine hair and sheer fabric (tulle, chiffon) are hard to key. Pick something else if you can. If you cannot, test it first.
• Bring shoe covers or clean shoes. A green floor gets dirty fast, and a mark is a mark in your key. Mirage3D's house rules mention shoe covers on the green screen and €200 for damage to the green paint. So read your studio's house rules before you go.

Camera settings

The more image information, the better the key. If you can, record in a codec with little compression and high colour sampling. Use a fast shutter speed with movement to limit motion blur; those soft edges are hard to key. Focus on your subject, not the background. A slightly soft background is actually fine, because the texture of the cloth or paint drops away.

What else should you bring?

• Tracking markers if your camera moves and you want a 3D background to move along later. Ask whether you can stick markers on the green.
• A monitor with a live key helps a lot. You see holes or fringes straight away. Some studios have a control room; according to the studio, Westgate Studio 1 in Amsterdam is chroma green as standard and has its own control room.
• Sound. Big, hard rooms echo. Ask about acoustics if you record dialogue.
• Test shot. Do a short test at the start of the day, key it on a laptop and check it works before you shoot all day.

Which studio fits?

Start with what needs to be in frame, then choose size and height. Pre-lit or not decides how much gear and time you need to bring yourself. Studios with a cyc or limbo lists them side by side, and renting a green screen or cyclorama explains the difference. In the UK this is often called green screen studio hire; it is the same thing.