on Aug 17, 2015 at 4:00:18 am Last Edited By Mark Suszko on Aug 17, 2015 at 4:02:31 am
I see your pictures. I still don't have a really good idea of the size and shape of the entire room, but, you might have to put the actual camera outside the doorway, like the way you shot the still, to have enough z depth to get proper separation distance between screen and talent, while still having room to light the talent. You diagram shows the side-lighting at a near extreme position: one of them might need to come forward a bit more for a proper key.
I'm of two minds regarding the umbrellas: they could be used to light the green screen more evenly, leaving you to use other fixtures to light the talent. But those two alone may not be enough to do it.
You could light your talent in a waist-high shot using one strong light, with a piece of diffusion material across one half of the front, and a bounce card for filling-in the face, by bouncing the un-diffused light off the reflector, back to the "fill" side.
If this is a green set you intend to use many times, Invest in some fluorescent tube fixtures, aligned vertically and washing across the green from either side... They could be fixtures from a home center, as long as the tubes have a high CRI rating, you'll be fine.
Look at the lit shot using the zebra bars feature of the camera, to see how even it is.
The most VITAL thing is to light that green evenly, and not overly-bright, but well-saturated. Second thing is to reduce spill from that green on your talent, by adding 2 feet to their height and making that the distance between the screen and the body.
Remember that you don't need miles of green around the body for a usable key, just enough so the arms and elbows don't poke past the edge. The rest, you use garbage masks and crop tools to remove.