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-   -   Color of work lights (https://www.dvinfo.net/forum/photon-management/54196-color-work-lights.html)

Greg Barton November 10th, 2005 11:32 PM

Color of work lights
 
I'm going to be shooting a scene using a greenscreen, where I'm going to use home depot work lights to light it. Will this work? All I'm using are the standard bulbs that came with the lights (I think it's two 500w bulbs). What color are these lights? Thanks.

John Jay November 11th, 2005 04:06 AM

Well Ive seen 'em in yellow black 'n white :)

If you mean the colour temperature rating of the bulbs , then if they are the J-type ;they will be 2800K if made by Osram / GE

I happen to know this because the J-type 250W 78mm size fits in a Redhead OF lamp and lasts 2000hr.


If youre after even illumination of a green screen, why not make two light strips from Dichroic reflector type - 10x50watts wired up like xmas lights but in a line.

Sean McHenry November 11th, 2005 09:05 AM

There is a standing thread someplace on these boards where we talk about color temp and using green gelled lighting for green screen etc. Do a quick forum search for that. Should be just fine but light the screen as flat as you can. Diffusion is your friend with work lights.

Sean McHenry

Glenn Chan November 11th, 2005 05:45 PM

Random ideas:

1- If you already have the work lights:
To diffuse them, you can try a variation. Build yourself crumpled tinfoil reflectors. The tinfoil reflects a lot of light compared to matte surfaces. The crumpling increases the softness of the light, and decreases its directionality.

The nice thing about is that it gives you soft + somewhat directional light (which gives you more effective light output). I'm not sure if the directionality may be a bad thing though- you sort of get a hot spot. If you aim the hotspot at the opposite side of the screen, I am guessing it would turn out perfectly. There isn't much of a hotspot anyways, and I'm guessing it would be comparable to fluorescent lights (un-diffused).
The nice thing about this is that it's cheap- get some cardboard and glue/tape some tinfoil onto it.

2- If you want to use the lights a lot, you might want to look into plant lights (fluorescent). The low CRI rating probably means that the light is very green, and it's only the green light that lights the screen.

Fluorescents have high light output / wattage (plant lights even more so), run cool, and are naturally diffuse.

They might be more expensive than the work light method though.

3- In the using green light thread, it was inconclusive whether really saturated green light helps. If someone were to do a test we'd know for sure.

Certainly I don't think it would hurt to use really saturated green light. Plant lights is a cheap way to get somewhat-green light (no expensive gels to buy; high light output naturally). Or you can gel plant lights too.

4- The green light may be missing the important parts of lighting a green screen. Green light probably doesn't make an important difference.
Light it even
Make sure there is no green on talent/wardrobe
Move talent away from the screen to reduce spill
Reduce spill by lighting the green dimmer. With some keying software, it may be better to light bright.
Keying software makes a difference. 4:1:1 color smoothing (for DV), difference keying, etc. are some tricks that make some software better than others. You probably shouldn't depend on keying software to fix problems though... it should usually be cheaper to light it right.

Cody Dulock November 11th, 2005 07:37 PM

it will say on the back of the work light usually... mine are 3200k

Sean McHenry November 12th, 2005 01:12 AM

Around these parts, the hardware stores are carrying flourescent work lights in both a dual tube somewhat short version like the old style incandescents and a longer single tube version. I bought one of the dual tube versions as they have individual switches for each tube and an outlet for stringing them together.

The bonus is, they are 5000 deg. K so the papers say. Not really super bright but a nice close up lamp for a face light or soft fill for daylight.

Sean


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