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Lighting Green with Green
I’ve been using a portable green screen muslin/cloth in the field for interviews, lighting it with two Arri 300s with fairly good results. In the studio I use KinoFlo lights with green lamps to light my wall painted with Rosco Chroma Green Paint with excellent results. So I wondered if I could use green gels on my 3200k lights in the field for better results on my cloth. Rosco #389 green gel is the answer. Adding it to the lights gives better saturation for better isolation in the chroma key process. Be aware, they are dark and will cut your light output by about 50%. So move the lights closer or use bigger lights to achieve the luminance level you like. I usually run it 40%-50% IRE.
Below are my results on the Vector Scope.
Bars & Tone
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5 Replies
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IMO making your light more ‘green’ doesn’t do anything to improve keying, and might even be counter productive producing unwanted green light falling on your subject. Also CK green paint is formulated to be lit by 3200k lights. If you spent money for specialty paint, you are wasting that money by lighting it with the wrong color temp light.
The secret to good green screen (or blue screen) is how even the lighting is, and having enough separation between the BG and the subject. Save the cash you spend on all this, and use it to buy a light meter, and use it to make sure the lighting is as even as possible.Scott Sheriff
SST Digital Media
Multi-Camera Director, VFX and Post ProductionThe Affordable Camera Dolly is your just right solution!
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We feel it was well worth the small investment, particularly in the Kinos with the green lamps. 90% of our work involves interviews on a green screen in the studio and in the field. With the green lamps we can achieve a better distinction in the keying process between the green background and some bit of green in their clothing or jewelry. This saves us time from having to try to custom matte small bits later.
We’ve seen no complications or additional spill with the green lamps, if anything we’ve noticed less spill. We do keep our subjects at least eight feet from the background and light for a level line of luminance on the waveform usually around 50 IRE. You’re right, “The secret to good green screen (or blue screen) is how even the lighting is,” that is Rule #1. We are just trying to help and speed up the keying process in every way we can.
Thanks for your input.
Bars & Tone
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Hey, if it works for you, it works for you. My concern would be that since the gels cut the power of the lights, as you say, they have to be brought in closer; to me, that makes it harder to light the wall or cloth evenly, creating spot areas in the center of each beam that will be a bit higher.
I have always thought the best greenscreen would be one that is translucent and lit from behind, with no lights in front except for lighting the actual talent.
They used to do some bluescreen this way in the old days of the Cineon process, as I recall, but that was for big budget Hollywood studio productions.
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The Vector Scope results look good, but I wouldn’t recommend running the green with that much intensity. You could wind up with making the hair look un-natural. However, if you are happy with the final matte, I then you are doing it right.
Brad Wright is software engineer, so it may be difficult to understand what he is saying. He is always happy to explain his greater detail.
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I’ve only had a couple of people out of about 70 that I had a little trouble with their hair when keying. It didn’t occur to me that it might be the intensity of the green. I’ll have to try some more tests. Thanks for the tip.
Bars & Tone
SALUTE!
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