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-   -   Setting up the lights for Chroma key screen shoot (https://www.dvinfo.net/forum/photon-management/144610-setting-up-lights-chroma-key-screen-shoot.html)

Ansab Khan February 25th, 2009 01:34 PM

Setting up the lights for Chroma key screen shoot
I'm trying to set up my chrome Key screen and the lighting in my apartments living. The lights which i will use are:

Soft box lights (Quantity 2) (Total = 2000 W/120V)
Work lights on tripod stand (Quantity 2) (Total = 2000 W/120V)
Spot lights for the subjects (Quantity 2) (Total = 1500 W/120V)

Can i do this set up in my apartemtns living room? Using one or two power supply riceptricals, so that i don't get a breaker trip on my distribution panel.


Battle Vaughan February 25th, 2009 05:24 PM

The main considerations are: very even lighting on the green screen, and a very flat, even surface that is the screen itself (i.e, no wrinkles, bends, shiny spots, etc). The softboxes sound good; I think you have way more watts than you probably need altogether unless you have a way big screen....our web people have a little video studio with an 8 ft. greenscreen and light it with two 600watt softboxes and the talent with a couple of 300 watt fresnels plus a backlight....../Battle Vaughan /miamiherald.com video team

Ken Campbell February 26th, 2009 01:44 AM

As BV already said, you can get away with the two softboxes placed in such a way to evenly illuminate the screen. Most likely the worklights won't work because they could be of a different color temperature than the softboxes and the light they give is very uneven.

I get my best results when the talent is as far away from the screen as possible and they have a little more light on them than that on the screen. The theory being that you are looking for max chroma from the screen, not max luma. I hope you have a big apartment!And it is always a good idea to have a backlight on the talent to help separate them from the screen.

Even with optimum lighting, getting a good key from DV or HDV is still not a cakewalk. A lot still has to be optimized in post.

Michael DiLieto October 18th, 2012 12:34 PM

Re: Setting up the lights for Chroma key screen shoot
I have the same questions basically.

Can I use softboxes with CFl's 5500k for the green screen, and then use, halogens for the talent? ( im thinking generally mixing color temps is a bad thing, but in the chroma environment is that ok?

Also, which I noticed soft box kits with 6500k lights versus 5500k lights. Which do you reccommend?


Paul R Johnson October 18th, 2012 12:47 PM

Re: Setting up the lights for Chroma key screen shoot
If none of the front light for the talent falls on the screen, then it's fine, because you set the exact key colour from the video, it only gets tricky when the space means shadows where different colours take over and are visible. For example, you'll probably get away with 3200K Fresnels on the talent and other 3200L lamps on the screen, if the edge of the Fresnels does hit the cyc - the soft edges will let it blend, and unless there's a hotspot, the key will work. If the edge of the Fresnel beam is a different colour, then the key goes a little adrift - and you have to widen the key window, which usually spoils the fine detail keying.

Henry Kenyon October 20th, 2012 01:35 PM

Re: Setting up the lights for Chroma key screen shoot
I've found the biggest challenge is preventing spill. The green screen reflecting back onto the subject. When I light the screen separately,it is too much. What finally worked is two Lowel Omnis (500watt each) placed at the corners partially lighting the subject and mostly lighting the screen. Two 100 watt inkies opposite corners over the background stands as hairlights (a little wider to cover the whole subject). Then positioning the subject distance from background to get the the proper exposure of subject and background.
If the subject is too close to the camera, the background won't be bright enough, if too close to the background, there will be chroma spill.
The farther back the Omnis are away affects the entire balance. Farther back prevents spill but may be beyond the exposure setting you want.
But just the two mains and two "hair" lights are a real fast and simple set up.
It takes experimenting because each room will provide a different amount of ambient light and reflective factor.

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