I'm just about to start a series of walk-on green screen shoots. These will be on-location all over the USA. Since I'll be flying all over I want to minimize what I take, yet not have to rely on rental houses in each location. These will be full-body walk-on shots of one person, so the green screen will be 12'x20' on a portable frame. The question is lighting the screen. I'm thinking of 2-4Bank Kino Flos with 525nm green lamps, one on each side, or suspended from another cross-bar on stands in front of the green screen.
From the Kino Flo catalog:
"Where do I place the fixtures?
The general rule: about the height
of the screen, half that distance in
front at a 45% angle. So if the
screen is 20ft (7m) high, the lights
would hang 8-10ft (3-3.5m) in front
of the screen. Generally, the 4ft
fixtures are rigged 2–3ft (1m) apart
in a row. On screens lower than
20ft (7m), one row across the top is
sufficient. For better evenness and a
brighter screen, a row of
fixtures may be placed along the
bottom as well."
Would 2 4Bank fixtures provide enough illumination to evenly light the green screen? Will this be portable? Would 2 Diva-lite 400s work as good and be more portable?
BTW, the camera is an EX1 shooting in a vertical orientation
Re: Portable green screen by Dennis Size on Apr 2, 2008 at 6:43:21 pm
Considering the detail of your original post, everyone's silence speaks volumes.... although asking if a DIVA should be used instead of the 4 bangers belies your experience. Why not just use Image 80's?
When lighting a 12'-0" x 20'-0" nothing could be considered "portable". Why so high? Why not a 12'-0" by 12'-0"? Why worry about the greenscreen and not consider the very important talent walking in front.
Incidentally, with a 20'-0" high greenscreen I would light from the sides and overhead, or just double hang overhead to compensate for separate lighting for the top and of bottom of the screen.
Re: Portable green screen by Philip Borgnes on Apr 2, 2008 at 7:19:49 pm
Thanks for the post Dennis.
I need to clarify a couple of points:
The 12x20 greenscreen will be up about 10feet off the ground, just enough to give headroom for the talent. So in effect the screen will be 12x10.
I have not used 2 - 4Banks with green tubes to light the screen. I have used 4 soft boxes with 500w lamps to light the same size screen. So you are right, I don't have that specific experience with Kinos on greenscreen, but have used kinos before for keys and fill.
My goal is to minimize what I do need to carry for lighting. In looking over other posts of folks that are doing something similar they seem to agree that renting the lights locally is the preferable thing to do, so I'll probably do just that.
In terms of the talent lighting, that is of course paramount and they will be lit separate from the background.
I just don't know if 2 kinos are enough to light the screen, but I agree 4 would be better. Just trying to keep the budget down without sacrificing quality.
Re: Portable green screen by Dennis Size on Apr 2, 2008 at 7:57:22 pm
Now I'm really confused.
Maybe it's just me, but I'm having a hard time visualizing how the greenscreen is actually playing above the talent.
Be that as it may, it's always a hell of a lot easier renting what you need at each location, the only problem is consistancy. You might not always be able to rent same Kino's at every location (or even find Kinos).
That being said you will need more than 2 Kinos for even coverage, and frankly the 4 light units will be too bright. Just rent (or even buy) 4 Doubles and that will be all you need.