Green Screen and Kelvin

[Christoffer Glans]

Shooting a studio green screen this weekend and I had planned some daylight HMIs for the occasion, but now there seem the budget doesn't hold for more than tungsten. So I'm wondering...

The Weapon 6K is rated to 5000, that's where you benefit the most in terms of color quality and so on. Having daylight sources creates a much cleaner image with better colors, which seems perfect for green screen. What kelvin are people mostly using for lighting a green screen?

 

[Michael Tiemann]

I'm not the world's expert on this topic, but I have shot green screen three different ways, and I've found that, counter-intuitively, tungsten actually works best. That's not to say that there aren't important reasons to prefer HMI (or daylight) generally. But in the specific case that you need to light a green screen, the advantage of tungsten is that when the illuminating lights spill, they spill light that is farther away from the green screen spectrum than daylight or, ahem, using colored LEDs set to green. Spill from the green screen is of course always a problem, but if there's spill from the lights illuminating the green screen to your subject, then if that spill is tungsten, it's easier to keep that from weakening the separation between the subject and the screen. When I used green LEDs, I didn't waste a lot of energy driving light into the screen that would otherwise be absorbed, but I also wasted a lot of time with green spill hitting the front of the subject that would have otherwise looked like just another light source had it been tungsten (or daylight).

 

[Ignacio Aguilar]

Maybe you can do well with tungsten if you use something like a 1/4 blue gel on the light units and a 80D or C (if you have enough light) filter on camera. That should be close to 5000 kelvin.

 

[Patrick Fougere]

This question peeked my attention, I'm a newbie and haven't worked a lot with green screens:

Does it really matter? I would think that all RAW footage isn't baked in with the temp. I would think that you could light your scene as you wish and mask the green screen in post using software like Davinci Resolve?

 

[Phil Holland]

If we are talking anything other than Mysterium-X, you likely are fine. I shot plenty of green screen and blue screen under daylight and tungsten without the need of filters.

MX however, if you are looking to achieve the best results under tungsten, use a blue filter.

 

[David Mullen ASC]

The main advantage for lighting with daylight sources is the lower noise in the blue channel (a bigger issue for blue screens as opposed to green screens.) So if you can't light with daylight sources, then light with tungsten and use a lower ISO setting, then the noise will be lower in all the channels.