Cinematography Mailing List - CML

Bouncing Light Off Black

15th March 2003

I haven't had the pleasure of experimenting with Black Silks yet, but I can understand the theory of their effectiveness outside...Nice to be able to diffuse the sun while not creating a huge white source.

But, I'd like to get your opinions on Bouncing light off of black. I gaffed a feature a couple of years ago where the DP asked me to bounce a light off of the black side of a black / white foam core for fill. I'm still not sure if I get the theory or reasoning behind this practice, although I've read about and heard of many DP's using this method.

Any ideas?

Toby Birney
L.A., CA and Vilnius, Lithuania

> But, I'd like to get your opinions on Bouncing light off of black.

We had this discussion a few years ago when the visual efx DP for "Alien Resurrection" bounced Maxi-Brutes off of large panels of black wrap to light the spaceship models. Mostly what you get back onto the subject is HEAT more than light.

Since the quality of a soft light is mainly determined by the size of the effective "source" relative to the subject, and the color that might be picked up by the diffusing technique, I was of the opinion back then that it was a rather inefficient way of obtaining that lighting effect. But if it gets you the look you want, who am I to judge....

David Mullen
Cinematographer / L.A.

I'm trying really hard not to say Emperors clothes.

I'd be interested in looking at a very sheer overhead black silk - I too have struggled with overhead 1/4 grids, china silks etc, I'm currently using either a white net or solid black depending on the shot - but would love to find a 'middle' option.

But for bouncing? ... … …Emperors clothes

Tony Brown

Maybe they're trying to get a soft specular source by bouncing off a black surface with a little bit of shine to it.

Bouncing Maxi brutes off panels of black wrap seems very odd, though. Sounds like one of those things you do when you order a ton of lights only to discover that the situation calls for a single tweenie at full flood.

Art Adams, DP [film|hdtv|sdtv]
Mountain View, California - "Silicon Valley"

Maybe this could be a way of increasing ....or is it decreasing the amount of negative fill...bouncing a couple of big sources off a black floppy. I once heard of a guy who lit using polystyrene (styrofoam)sheets as the diffusion, said it gave a wonderful soft light....and I just bet it did as bounce least until the poly melted.

As to black silk on a zip to give the light direction, wouldn't you just use an 'egg crate' snoot (honeycomb snoot I think in U.S. speak) you can soften the light even more by putting the diffusion behind the snoot.

Like the old trick of putting the diffusion behind the barn doors of the lamp... right next to the lense...diffuses the light but keeps the direction. As for reflections in the pupil...unless you are on an E.CU of the eye, is it a problem?

Graham Rutherford

Graham Rutherford writes :

>I once heard of a guy who lit using polystyrene (styrofoam)sheets as the >diffusion, said it gave a wonderful soft light.... and I just bet it did as >bounce least until the poly melted.

I was recently rummaging through the local plastics shop and found a sheet of  2-by-four-foot, 1/16"-inch thick polyethylene (polythene, to the Brits). Thought I'd try using it as a diffuser (well clear of any hot sources!). Though it was heavy, and a bit hard to handle because of its floppiness, It worked fine.

But it also had a peculiar characteristic: As seen from the subject's POV, the color of the light remained as it should -- except for the hotspot in the middle, which was decidedly reddish! Somehow this material was passing the full spectrum as a diffuser, but where the light rays passed through in the straightest trajectory it was transmitting a lot more red!

Dan Drasin
Marin County, CA

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