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My First Green Screen -- Help?

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Andy Bernstein
My First Green Screen -- Help?
on Dec 7, 2007 at 6:36:17 pm

Hi. I need to create several hours of online training video content, and wondered if I could do it in my office so that it's easy to produce regularly but still have it look good. A friend has the following gear:

4 Britek halo flood twin 600 lights (300w, or 600w with both bulbs on) w/ 2' softboxes and barndoors
1 Britek 200w light w barndoors
Tripods for the 5 lights above
2 1000w twin head utility work lights on stands (2000w total)
10'x20' green screen muslin on stands

The room we would use is 14'W x18'L x 9'H. Our goal is to shoot green screen footage, some of it full body, and then key it in FCP and Ultra 2. The subject is white with dark hair and will always be wearing a dark suit.

Do I have what I need to light it evenly, or would you recommend buying more/different lighting? We have a 3CCD miniDV camera but I'm going to post in another forum to see if we should be upgrading that in order to get a clean key.

If you need more information, please let me know. Thanks in advance for your input. I really appreciate the help.


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Bob Cole
Re: My First Green Screen -- Help?
on Dec 9, 2007 at 1:51:03 am

[Andy Bernstein] "I need to create several hours"

I hope you have lots of prep and test time because you'll need it. None of your elements -- lights, background, and room -- sounds adequate to the task.

Are you producing several hours of green screen? That's lots of compositing time. You might look at hardware which keys the live image.

You might want to google this topic or search this forum for basic advice about shooting a green screen. I'm not familiar with your lights, but it sounds as though the key light is going to be hard to keep off the green screen, especially given the room size and a full figure shot. The actor would practically be standing next to the greenscreen. Also, a fabric doesn't "cyc" well, or sweep to become a floor.

I'd shoot a test right away, because I don't think you have what you need for a bulletproof key, and with several hours of material, you'll need a bulletproof key.

Bob C

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Andy Bernstein
Re: My First Green Screen -- Help?
on Dec 12, 2007 at 2:30:41 am

Thanks for the input. We're creating a series of short training videos using Ultra 2 and their virtual backgrounds. We started playing around today and already tossed the 1000 watt worklights (too hot). We're going to get a couple of Lowel Totas instead. And we may end up doing just tight shots and not full body because I can see that the room isn't big enough and the green screen on the floor is tricky to light well in this space. If we need full body shots to establish the virtual set, we'll do that elsewhere.

If anyone has other tips, I'm all ears. Trial by fire here, but we have some time to figure it out. Thanks!


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Bob Cole
Re: My First Green Screen -- Help?
on Dec 12, 2007 at 2:44:12 am

Sounds as if you're making progress!

[Andy Bernstein] "We're going to get a couple of Lowel Totas instead"

For keys or background? For key lighting, I'd advise against those, unless you're putting them in Chimeras. For background lighting, you could do better with some Mole Nooklites (often available on eBay) or other cheap old open faces WITH BARNDOORS to keep their light from hitting your subject.

"already tossed the 1000 watt worklights (too hot). "


For cooler key lighting, check out some fluorescents from Kino Flo or Lowel. You don't need the Diva, with its self-contained ballast, because you're in a studio. You could get one of Kino Flo's four-foot-long, separate ballast lights, which would allow you to wash your subject in light which drops off quickly so it minimally affects your background.

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Andy Bernstein
Re: My First Green Screen -- Help?
on Dec 12, 2007 at 2:57:09 am

Hi Bob,

I appreciate the input. The Lowel Totas were for the green screen. I'd heard good things about them, but I'm sure the Nooklite would work well too. I'll probably buy them new at B&H in the next few days. I can get 2 750w Totas with umbrellas and stands for around $350. The 1kw Nooklites are $200 each (and barndoors are another $50 each). Is there a significant difference in performance?

I'm going to use the Britek lights and softboxes for key lighting. So far they haven't given me any trouble, but I'm learning as I go here.

Best,
Andy


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Andy Bernstein
Re: My First Green Screen -- Help?
on Dec 12, 2007 at 3:03:25 am

I just noticed that there are 650w Nooklites too for $142 each plus barndoors ($40), bulb, stands, etc. I'm leaning toward the Lowel Tota kit but am curious to hear if that's an unwise decision.


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Bob Cole
Re: My First Green Screen -- Help?
on Dec 12, 2007 at 3:10:16 am

I really wouldn't spend that much, especially for less-than-ideal lights. I have used Tota lights for lighting a background, but I wouldn't do it on purpose because it is difficult to control stray light. It isn't very even on the background, and from the side, the bare bulb inevitably hits places you don't want, like the lens or the subject. The Tota light in umbrella idea sounds great until you try it: lots of stray light, not enough light (for all the heat generated) on the subject. A good durable broad light with barndoors would be better. You can get open face broad lights on eBay (or perhaps Craigslist) for nothing. I am not trying to sell you here, but I have about six such old Colortran lights I won't even try to sell on eBay because they'd net so little money for the hassle.

Ideally, you'd get a light designed for the purpose; I hope one of the lighting design experts chimes in here, but I think you'd want a cyc or a scoop -- but a couple of good old broads like the Mole Nooklites would be just fine.

another idea:
If you have a permanent location, hanging your background lights from the ceiling would make the floor much easier to navigate. And once the background is evenly lit, having the lights somewhat inaccessible would keep people from moving them accidentally.


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Dennis Size
Re: My First Green Screen -- Help?
on Dec 12, 2007 at 3:41:07 am

Someone actually told you that the Tota-lights were good? Obviously that was someone trying to get revenge on some other sucker who didn't know any better. The money you save on the fixtures will be doubled buying antiseptic burn ointment, so be prepared. However once you own them you'll find that after you stop using them for lighting you'll be able to use them to cook your Christmas goose.
You could save all the aggravation and just do it right with Kino Flos.
If cost is that crucial then resort to a good old fashioned scoop. You should be able to buy 10" scoops used for well under $100.00, and they'll work great. Whatever source you choose you'll need at least 5 for a greenscreen that wide....but only two 8'-0" Kino Singles (hint-hint).

DS



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Andy Bernstein
Re: My First Green Screen -- Help?
on Dec 12, 2007 at 4:27:58 am

Hmm. Okay, forget the Totas and let's start over then.

Let's say I'm using around 5' of the green screen to focus on an upper body shot. I don't need to light the whole width, and will matte out the rest of the shot. Keep in mind this is my living room, so I can't/won't install anything permanently and am hoping to find something I can just take apart and stick in a closet when I'm not using it. Would a couple of smaller Kino Flos work well? And, more importantly, do you think I can realistically make this work in my living room? Because if not, we're talking about renting a studio and then I wouldn't want to have bought more lighting.

Gratefully,
Andy


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Rick Amundson
Re: My First Green Screen -- Help?
on Dec 12, 2007 at 4:41:25 pm

Andy,

This is totally doable in your living room. Here is my thought. I, too, am not a big fan of the tota light. The secret to getting a good key is to make sure the chroma key screen is lit evenly. The best way I have found to achieve this in a small space is by using 2 lights on the background, one from either side, with diffusion on them to help spread and soften the light. Try something like Opal or 250. This is where the barn doors come in handy. I have used both open face or fresnel lights. Either works but you don't want more than 650w per light in this scenario.

Next, find the 70 IRE level on the background by using the zebras in your view finder and stop down to the point where they just disappear. As you open and close the iris, the zebras should appear in a uniform manner across the green, if they don't, the green is lit unevenly.

Once you have an even background, set the exposure just below the 70% zebras and light the foreground element to this level. Be sure to flag the foreground lights off the chroma key screen. This is why the Divas (or something similar) is so great for the foreground lights, they are soft, flattering, cool and drop off in a hurry so there is less flagging required.

One last piece of advice. If you go with an open face light for the background (i.e. nook light, tota, etc.) be sure to get a protective screen for the front as these have a tendency to explode and will melt you carpet.


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