Blue vs Green Screen

 In film, the determining factor may be the colors of the subject (contrast to screen). In television and video work, the color green has traditionally been used for chromakey work.

Why use CineFlo and Cineflo XT to light a blue or green screen?

For the best results the screen needs to be lit evenly and with the best possible color saturation. Evenness is easily achieved using CineFlo lights because of the soft quality of the light and the wide beam spread. The best saturation of color is achieved by using blue-spike lamps on blue screens and green-spike lamps on green screens. It’s not as much about how much light is used to light a screen, but rather what produces the best saturation of reflected blue or green light.


Other benefits of using CineFlo?

 Benefits include: ten times more light per watt than tungsten lighting; manual and DMX remote light level control without color shift; fast set-up; low power consumption; low heat; and cost savings from not using color gels.

Which fixtures should I use?

Because lighting screens is about evenness, you generally want to use bigger fixtures with the widest beam spread. For portability and versatility, 4ft/4Bank Systems fixtures have been the most popular units for blue and green screen applications.

However, depending on the size of the screen (especially in installations) Double Systems (4ft, 8ft)
and 4Banks (4ft, 8ft) can beused. Sometimes choosing the appropriate fixture is based upon the size of the screen that needs to be lit. Bigger units covering more area become more economical.
Diva-Lites with their smaller profile and ParaBeams with their more directional beam can also be used, but the results usually are not as efficient as Image fixtures.

If blue and green spike lamps display the best saturation, why not use them 100 % of the time?

There are times when the subject is very close to the screen or standing on a cyclorama with a floor painted blue or green. In these cases where it is impossible to keep the light from contaminating the subject matter, we recommend using our KF32 (3200K) Lamps. The KF32 Lamps deliver all the benefits of evenness, but they do not have as much contaminating red spectrum as tungsten hot lights.

Where do I place the fixtures?

The general rule: about the height of the screen, half that distance in front at a 45% angle. So if the screen is 20ft (7m) high, the lights would hang 8-10ft (3-3.5m) in front of the screen. Generally, the 4ft fixtures are rigged 2–3ft (1m) apart in a row. On screens lower than 20ft (7m), one row across the top is sufficient. For better evenness and a brighter screen, a row of fixtures may be placed along the bottom as well.

Is there light drop off in the middle of the screen?

Use a spot meter, not an incident meter to get readings. Our experience has been that if the fixtures are properly placed we have not seen more than a 1/10th difference (spot meter) from top to bottom of screen. On screens 40ft (13m), the screen is evenly lit having one row across the top and one row across the bottom. For taller screens 60-80ft (20-26m) an additional row may be placed on the top and angled more towards the center. Sometimes when units are placed on chain hoists, the lights can be moved to light the screen and still be out of camera view.

Do I need to light the subject separately from the screen?

Yes, the screen should be lit first to the light level required. Then the subject should be lit separately.

What is the light level for the subject and the screen?

For best results shoot a density wedge test to determine exposure for the screen. Generally people shoot at key for greenscreen, or underexpose the shot as much as 2/3 f-stop to 1 f-stop under key. Bluescreens are underexposed 11/2 f-stop to 12/3 f-stop below the key light level.

What should I use to light my subject?

You can choose any light for the subject. But once the screen has been lit, try to keep stray light off the screen. In many cases CineLight's are used to illuminate the foreground subject because the soft quality of fluorescent's drops off and doesn’t spill unwanted light onto the screen.

VideoGrip.net - European supplier for Video & Film lighting equipment | Prices excl. VAT.
bank_transferSolution Graphics ebay_feedback