Diffusion demo

Following is a brief demo of various panel materials I use for tabletop and portraits. I have settled on 2'x3' frames as being large enough to get the job done while remaining maneuverable. Plus, they're cheaper. Light source was a Profoto AcuteB 600 @ 150Ws with standard zoom reflector. The base ISO of 100 was dialed upward to correct for light loss for each material under test, and color was also corrected in camera. Both were tweaked further in post to appear matched in those attributes. The differences of interest for this demo are shadow transition and degree of fill.

The setup (shown later) has the panel about 3' from the subject scene and the light source 2' beyond the panel. List of meterials: double scrim, china silk, artificial silk (aka polysilk), Rosco frosted sheet plastic. Light loss varied from 1-2 stops. Here is an animated GIF of the results:

Have you tried just using drafting paper?

I've used it in the past when I needed large panels. I would use 1/2" pvc to make a frame and glue the paper to the frame.

Interesting demonstration of what effect the different materials have on an image. I did get a kick out of the $20 bill flapping though.

So, use bare bulb or scrims if you don't want the room to be mirrored on round, polished surfaces?

bigVinnie wrote in post #17976172
Have you tried just using drafting paper?

I've used it in the past when I needed large panels. I would use 1/2" pvc to make a frame and glue the paper to the frame.

Paper is a fine material in the studio, although I use it for bounce and also for shoot surfaces (like this demo). Tough Rolux may be plastic but I really like it for its lack of color cast, diffusion quality and handling (waterproof, strong, curl free). My roll is 4' wide, so good for pretty large constructs. Rosco has a wide selection of plastic sheet.

Alveric wrote in post #17976265
So, use bare bulb or scrims if you don't want the room to be mirrored on round, polished surfaces?

Smart ass. I wanted something mirrorlike to show the actual light source, and to monitor the degree of stray light (panels can generate a significant backblast). I wasn't actually modeling curved chrome which, as you know, is the top product headache to photograph. Those professional glossies of chrome appliances require a color-neutral set that resembles a complete kitchen, including a ceiling with cans. I'm not quite there, yet!

I wanted to demo panels because I think they are far superior to softboxes (which I no longer use). The latter can completely suppress stray light, but that is not always desirable, especially since light needs to be shaped with flags in any nontrivial setup anyway. Panels in all these forms can also be used with sunlight.

Nice demo.

Thank you! It took several hours, including the post work, but I was interested to see the results, too. I also attempted to address Alveric's observation about ugly chrome reflections: total failure so far.

RicoTudor wrote in post #17976091
Following is a brief demo of various panel materials I use for tabletop and portraits. ...

I took the liberty of taking your five comparison shots and making a single composite in order to make it easy for everyone to visualize the differences between the panels side by side. I hope you don't mind; let me know if you mind and I will remove this post.

Thanks, Wilt, that looks perfect.

RicoTudor wrote in post #17977641
Thanks, Wilt, that looks perfect.

Yup, nice work.