Quality of Diffusion
 

Diffusion...many types, many materials.

Something I've always wanted to see is a side by side comparison of the differnt types of diffusion material.
All the same size and distance from the subject.

I would like to see the difference between 1/4 grid, tough spun, hamburg frost, etc.

Anyone aware of such a comparison?

I asked the same sort of question around the boards a year or so ago. "How soft is soft?", I think was my question. I was even criticized for asking it. I guess it's difficult to quantify since you would have to measure very small samples of reflected light (off the subject) to answer and we don't have the means to do that - it would take some sophisticated lab equipment to do it and then be able to afix some meaningful tag (say, "#3 Diffusion") to each type of material. The closest that exists already is diffusion gels, which can tell you how many stops you lose and presumably the manufacturers also have data on color temp, which will change, no matter which gel you use.

All I "know" is that multiple diffusion = better diffusion. If you are going to put a softbox on your fixture, or a frame of Tough-Lux in front of it, put an Opal gel in front of the lamp first. I've even used an Opal diffusion gel on the fixture, a 12" x 12" frame of Grid Cloth in front of that and a 20" x 24" frame of Tough Spun in front of that. Magic!

Spread is what its all about. The more layers of diffusion, the wider your light is spread which provides softer light. Size of the diffusion and distance to subject also play a big role. I've never seen a side by side comparison of how much spread you get from a specific type of diffusion. Barbizon.com has a reference chart for certain types of diffusion, how much light transmission is lost and how wide the light will spread. No actual photos though.

I use a photoflex medium nxt (double diffused) then place a wescott 39" x 39" translucent about 18" in front of the box. Very soft light.

Oooo... Nice!