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Help with fixing green screen lighting problems

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David Calo
Help with fixing green screen lighting problems
on Feb 10, 2010 at 2:12:51 pm

Hi. I'm new to the green screen and am filming my bands music video. I just bought a 10 by 20 green muslin and took some advice from a you tube video and bought 2 halogen tripod work lights that have 2 500 watt lights in each. I have them positioned about 5 feet from the sides to light the screen without the subject casting shadows. The problem is the lights make bright horizontal lines on the screen which makes keying a problem. Today I am going to buy some sheer white fabric to hang in front of the lights which i hope will diffuse the lines. If this doesn't work, do any of you have any cheap suggestions, as i don't have the funds, or the intent to be a pro photographer, and buy hundreds of dollars in pro lights. I'm not filming in hd or anything so i don't need ultimate clarity, just an even green. Thank you.


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Mark Suszko
Re: Help with fixing green screen lighting problems
on Feb 10, 2010 at 4:37:35 pm

Diffusers would be essential for what you're trying to do there.

People use all kinds of things for diffusion material, from spun glass cloth, dacron, or silk, to plastic shower curtains, to baker's oven-proof cooking paper. Be careful if your diffusion materials are not fireproof. While plastic shower curtain will make a nice diffuser, it is easy to melt it or make it catch fire.

Meanwhile, your diffuser, whatever it is, works better the farther in front of the point light source you can place it, because it makes the overall light emitting surface bigger. Right now your actual light source is the tiny 2-3 centimeter coiled wire inside the bulb. That's what makes the light so directional and harsh. When the same amount of light energy is coming off of a 3x3 foot area, you get a softer more pleasant and even light. So hang the diffusion material a foot or more away from the light and see how it changes the character of the light. I know this clutters up the set with more stands and other bric-a-brac. Which is why I like to say that a professional lighting instrument winds up cheaper and easier to use in the long run than home depot make-do stuff. The more work you do, the more you appreciate the precision control and faster work flow of using real pro lighting gear. Sure, you can make video with MacGyver stuff. But consider it only a stop-gap while you save up for the good stuff. And you can find good stuff used that will serve you for years. My light kit is over 20 years old and still works fine. After 20 years' amortization, the initial high cost works out to "free". And I really appreciate the time it has saved and the control it offers.

Another way you can do it besides diffusion is to bounce the lights off of white or silver foil-covered cardboard or foam core boards, but while this makes a superior soft source, you will lose a lot of the energy of the lights in the process, they won't reach or cover as far. This trick is better saved for lighting talent and not green screens. A better way to go on "cheap" green screens is to use long fluorescent tube lighting instead of halogens. The flo tubes already have a green spike in their spectrum, and the tubes are a softer, more diffuse light source as well.

or... Google "Bill Holshevnikoff" and "foam core soft light" for instructions on how to make a soft box attachment for your halogen light that will work almost as good as a Rifa or Chimera, for less than $10 in materials.



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Mike Cohen
Re: Help with fixing green screen lighting problems
on Feb 10, 2010 at 5:48:18 pm

or rent a proper light kit. I can get an Arri softbank kit for $75/day here in CT. You can't get something for nothing.

Mike Cohen


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David Calo
Re: Help with fixing green screen lighting problems
on Feb 11, 2010 at 8:58:45 pm

Thanks for your suggestion. I did end up getting some white sheer cloth and hung it about a foot in front of the lights. It worked out well enough for keying. When i get done with the video I'll post a link to it hear, it's already coming along sweetly...


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Dennis Size
Re: Help with fixing green screen lighting problems
on Feb 11, 2010 at 11:29:15 pm

Sometimes it's better to do a little research on what's the best tool for a job. If you were hammering in a nail you certainly wouldn't use a screwdriver to do the job right (although we all have).
When lighting a greenscreen, a soft wash is the quality of light you need (as has been said "ad nausem" in this Forum). Your first mistake was in buying harsh floodlights. Then you put yourself in the position of having to fix the problems you created using the wrong tool. You should have used softlights -- fluorescent being the easiest/best choice.
I can cetainly understand a novice not having the money to buy expensive pro tools (such as Kino Flo fluorescents) but you still should buy the right tool.
For the same money you spent on those cheap halogen work lights you could have bought cheap fluorescent fixtures. I just bought 3 double tube 4'-0" fixtures at Home Depot for $15.00 apiece. That would have done the same job for you without excessive heat being generated and power wasted; with relatively the same end result -- but not as much angst.

How did you actually light the band?




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