What's the best way to light a green screen with just a 3 point setup?

[AllAroundFilmLV]

I was shooting some green screen footage last week and was having some trouble getting the lighting even since all I was using is a Lowel 3 point setup (500w Omni, 750w Tota, 250w Pro). I ended up using the 750w to light the green screen which doubled as a backlight, the 500w as a key, and the 250w as my fill.

I had some terrible challenges with shadows on the green screen (I didn't have room enough to pull my subject forward to avoid this). But, more importantly, my 750w was placed on the ground and set as low as possible and the light was not even at all.

I was able to key out everything just fine (after a couple hours of tinkering), but I'd like to see if you guys have any tips to avoid these problems in the future.

rogar-Kriz(DBG):

 

[Matty_g]

There is no "best way"
This really depends on the shots you need and the space.

 

[Jon Starr]

Matty G's right. But here's some advice from the few times I've used greenscreen and seen others do it.

When filming a greenscreen, from my experience, you have to treat the greenscreen and the subject as two different subjects.

You need to have a separation between the screen and the subject. The same goes with lights. You have lights for the screen, then lights for the subject. This is the same idea for lighting a regular scene (background lights vs. subject lights). But of course things change around shot to shot, scene to scene, film to film. So saying absolutes is difficult.

Anyways, the separation is also to help avoid spill onto the subject which can be a pain. After all it acts as a giant coloured bounce.

If you don't have enough lights and no ability to keep a distance, well then what you did was probably best. I mean 3 lights is three lights, nothing will change that. You could have done without the backlight and focused on lighting the greenscreen, which will inevitably have a hotspot (which is why I use at least two lights well diffused on either side, or maybe use some strong kinos, just something with very little hotspots). Then use the other two lights as you normally would (key/fill), but you're limited in what you do. Always point it down from up high, keep it diffused, and try and angle it away form the greenscreen, and use blackwrap or flags to avoid any spill (and therefore shadows) onto the screen. But of course this depends on the distance.

 

[J Davis]

the lights on the green screen should be soft as possible. Use flos or umbrellas on your lowels. Two or more on the screen alone. Four is best.
Maybe avoid the rim lighting on your subject too. Fill and key is just fine.