Cyclorama or chroma key: which studio floor does your shoot actually need?

Two studio setups get confused more than any others, because both involve a large plain background. They do opposite jobs.

A cyclorama makes the background disappear. A chroma key backdrop lets you replace it. Book the wrong one and you either spend a day in post-production cutting out a subject that should have been shot clean, or you shoot on green and discover the scene you wanted to put behind them did not need replacing at all.

What a cyclorama does

A cyclorama — “cyc”, or infinity cove — is a wall that curves smoothly into the floor, with no visible corner. Lit evenly, the curve erases the horizon line, so the subject appears to float in an endless space: pure white, grey, or whatever colour the cove is painted.

It is the setup for:

• full-length fashion and portraits, where the floor has to be in frame without a visible join;
• product on white, including large products that will not fit on a table sweep;
• movement and dance, where the subject needs room to travel without leaving the background;
• clean interview and explainer video with a minimal look.

Getting a true white from a cyc is a lighting job. The cove is lit separately from the subject — usually brighter than the subject by about a stop — so it reads pure white without spilling light back onto the person. It also needs care: shoe covers on the floor, and a repaint when the curve gets scuffed.

What chroma key does

Chroma key replaces a single, saturated colour — almost always green or blue — with other footage or graphics in post-production. Everything that is that colour becomes transparent.

It is the setup for:

• presenters over graphics, news-style;
• talent composited into a location you cannot travel to, or one that does not exist;
• product in a generated or 3D scene;
• virtual sets for recurring content.

Green or blue?

• Green is the default. Camera sensors are most sensitive to green, so a green screen needs less light to key cleanly, and it holds up better with the compressed footage many cameras record.
• Blue spills less and suits subjects wearing green, holding plants, or with fair hair that green tends to contaminate. It needs more light.

The rules for a clean key

Most bad chroma keys are made on set, not in the edit:

1. Distance. Keep the subject well clear of the backdrop — a couple of metres or more — so the green does not bounce onto their shoulders and hair.
2. Light the backdrop and the subject separately. The screen wants flat, even light with no hot spots; the subject wants their own key light. One set of lights doing both jobs does neither.
3. No green on the subject. Clothing, jewellery that reflects, even a green logo on a mug. Anything green disappears.
4. Avoid wrinkles and seams in the backdrop; they key as uneven patches.
5. Freeze the motion. A faster shutter reduces motion blur on hands and hair, which is where keys fall apart.
6. Record the best quality the camera allows. Higher bit depth and less compression give the keyer more colour information at the edges.

Which one does your shoot need?

Ask what the background is for:

• Should it disappear? Clean white, grey or colour, nothing to add later → cyclorama.
• Should it be replaced? A location, a graphic, a virtual set → chroma.
• Not sure what goes behind yet? Chroma keeps the option open, at the cost of post-production time and a more careful shoot.
• Is the budget tight on post? Cyclorama. What you shoot is what you get.

Questions to ask before you book

• How wide, deep and high is the cove — and how far back can the camera go?
• Is the cyc lit for your frame before you arrive, or is that part of your hours?
• What colour is it painted, and is there a charge for a repaint after your shoot?
• How large is the chroma backdrop, and can it be lit evenly across your whole frame?
• Is lighting and grip included in the rate, or itemised?

Send the studio your frame size, the number of people in shot, and whether anything moves. A good studio will tell you honestly whether the floor covers it before you book.

Where we fit

Our cyclorama studio on rent in Bhubaneswar is lit before your call time, and our chroma studio on rent in Bhubaneswar lights the backdrop and the talent separately to keep spill off hair and edges. Both are part of our video shoot studio rental, with lighting and grip included in the rate.