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Old October 17th, 2008, 02:49 AM   #1
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What fixtures for Green Screen

Okay guys I got a ton of info from my last post about the Green Kino bulbs. I am ready to start putting together our Green Screen area. I want to mount permanent flourescent screen lights to the ceiling above the green screen. Is there a fixture I can use that will be silent without having to buy the whole Kino (or preferably Coollights) lamps. I know that standard Home Depot flourescent lights wont cut it, but are there any other alternatives?

Also any good info on where exactly to mount the lights. I expect to have a greenscreen that is about 10 feet high. I think it will end up being about 16 - 20 feet long on one wall and then around 8 feet down the second wall. How many lights should I mount on the ceiling and how far out from the wall should they be. I am looking for some suggestions for good starting points, unless there is already a pre-determined "best position"

Thanks!

Bill
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Old October 17th, 2008, 05:02 AM   #2
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Actually, I would say you can indeed find good adequate fixtures at Home Depot for this kind of lighting. And whether you use those or not all depends upon who is coming into your studio. Paying clients? Maybe you should think about a more professional looking fixture than HD can offer. If you're mostly doing your own work and filmmaking however, I think HD fixtures will work for you.

You can even most of the time find a suitable 4 foot T8 or T12 tube there too. Green screen lighting is not all that demanding, it just needs to be even. If it was me, I would have two rows of fixtures mounted to the ceiling and as many fixtures on each row as necessary to cover the screen for the given length of screen. The first row of fixtures closest to screen would be trained down at a 45 degree angle to cover as much as possible. The second row would be at (60 degree probably) the right angle to cover the rest down to the floor. Each of these two pairs would probably cover about 5 to 8 feet pretty well so you would need a pair for each 6 feet or so with overlapping.
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Old October 17th, 2008, 05:51 AM   #3
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Thanks for the excellent reply Richard. As usual you are open and honest rather than just plugging your own product line. Your reputation on this board is well deserved.

My only question is if the HD light fixtures will make any noise that will be a problem for us shooting video. I do not have to worry about clients coming into the studio and being disappointed. We shoot for one major client who appreciates our work and understands that the look behind the camera does not represent the final product. That support is great in a working relationship.

Do you have any specifics we should look for in bulbs at HD?

Thanks!

Bill
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Old October 17th, 2008, 06:53 AM   #4
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Hi Bill,

Lighting the screen will be challenging in three ways.
1. Keeping the light even over the screen.
2. Keeping any light from falling on the subject.
3. Keeping the light consistent during the shoot.

Setting up any light can be tough to make it even, setting up several to match a "quality" and "quantity" only makes it tougher. A light meter helps. Use a minimum of 4 lights, two high, two low, with wide dispersal, and take meter readings at several intervals. Ideally your variance will be minimal, less than a third of a stop.

You don't want that keyed material to light your subject either. It needs not to be the significant source of light for the subject. My general rule is there are two kinds of keyed material - realistic keys and non-realistic keys. The former is a special effect that you're trying to sell to the audience as "real", the latter is just audio/video convenience (I do it for my tutorials when showing something for clarity). Lighting the subject then becoming a part of selling the realism. You'll need to mimic the lighting of the material to be keyed to the background to the subject - sunlight, whatever - to match. Trick is, you might have to add a slight rim light to kill spillage. Some software in some CODECs, especially NTSC's DV's 4:1:1 is just a lousy to key CODEC, you might decide to add that slight rim keylight. C'est la vie.

Finally, consistent lighting is a hallmark of professional video lighting. Non-professional lights can and do drift during shooting in both intensity and color temperature. This, of course, can and will affect the quality of the final product of a longer shoot, especially one that has many scenes inter-cut into the final show. If the lights are to be used for a long time, check the quality of the color temperature and white balance often.

My best.

Mike
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Old October 17th, 2008, 08:34 AM   #5
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Quote:
Originally Posted by William Wilson View Post
Thanks for the excellent reply Richard. As usual you are open and honest rather than just plugging your own product line. Your reputation on this board is well deserved.

My only question is if the HD light fixtures will make any noise that will be a problem for us shooting video. I do not have to worry about clients coming into the studio and being disappointed. We shoot for one major client who appreciates our work and understands that the look behind the camera does not represent the final product. That support is great in a working relationship.

Do you have any specifics we should look for in bulbs at HD?

Thanks!

Bill
Thanks for your comments. I'm just realistic and I tell people what I would do if it was me. My products definitely have their place and they do look more pro and have more light control accessories than HD stuff, but the good thing is, you can drive across town to get one or two to try out from HD. If it flickers or makes noise (which is more unlikely these days) then you can just take it back and try another. They don't look like much but given a good electronic ballast, they put out the same type of light, noiseless and flicker free. If you pretty much stick with mostly the T8 types you should find that they will mostly be electronic ballasts and in most cases it will say on the package if its an electronic ballast or not. The fixtures I'm thinking about aren't necessarily the shop lights but perhaps the kitchen fixtures -- 2 or even better 4 bulbs. These fixtures will just be used to light the screen and then other types of light for the foreground / subject area. I haven't seen evidence of drift of color temperature with some of the better quality electronic ballasts and bulbs.

As for bulbs, I would say stick with a fairly good one and you can experiment with different color temperatures and see how that matches with whatever lighting you use for the foreground which will perhaps better be done with studio grade fixtures--tungsten, flo or whatever, barndoors, eggcrates and other light control hardware. You may find that CRI isn't as important on lighting the green screen as long as that's all your using them for. And that's what I was recommending, lighting just the screen with those kinds of fixtures. Remember, whatever you choose, you'll be primarily white balancing to the subject area lighting so whatever shift takes place in the green area because of that should be okay as long as it doesn't take the color of the greenscreen out of the range for a good key.
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Last edited by Richard Andrewski; October 17th, 2008 at 09:18 AM.
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