OT: Green Screen technology ??

Bob Greaves wrote on 3/12/2005, 7:29 AM
Has anyone ever attempted to make a luminescent wall? I am talking about a wall made of a material that glows with an even green, blue or red color.

I would wonder if lighting would be easier to produce if such a chroma screen were itself the light source at a low enough level to register evenly but without spill.

Or how about a back lit transluscent screen? Have these been attempted and found lacking, or what?

Comments

Spot|DSE wrote on 3/12/2005, 8:01 AM
Backlit, translucent or not, works quite well, providing the fabric or material is conducive. However....if it's a plastic material, you could easily run into issues of reflection from key light sources if you weren't careful, not to mention any other highlighted area in the shooting space.
I've backlit the Photoflex Flexdrop on several occasions, it works wonderfully.
Fleshpainter wrote on 3/12/2005, 1:23 PM
Reflecmedia (mentioned above) is agreeably the pinnacle of chromakey. Backlighting can be done too but if there are any overlapping seams in the fabric they will show up as the light source will be passing through more than one layer. So the fabric has to be one piece, and you can't use the floor area. If you need the floor the you're back to normal cloth and/or paint.
If you're looking at some other alternatives to you can light polyester with UV 4 ft. tubes in normal florescent fixtures. This is something you would do if you were using florescent colors on the subject, or doing some kind of silhouette-type work with UV cloth on part of the subject. I've used this technique a few times for special F/X, where the models were painted with UV paint, and dancing in slow motion.
I know... it was a dirty job, but someone had to do it.
The problem with UV backlighting is that you can't use normal lighting on your foreground subject because it washes out the UV effect. Even with a PD170 low light camera, and subjects lit with candlelight, it will wash the background out. Thus, the only application where this works well is where the entire scene uses UV lighting.