What to buy for a DIY rigid diffuser?

[andrgl]

I need to build a large, evenly lit light source. I own plenty of paper, cloth, silk, etc, but I need something that will make for very uniform diffusion.

Objective is to make a backdrop that can be rear lit with RBGW strips to dial in any color.

Currently using hard lights with gels but can’t shoot larger than 2 feet without hitting massive light fall off. And when I try to diffuse my lights I lose intensity big time.

 

Ideally I require:

- 3 x 3 feet or larger

- Neutral, no color casts

- minimal light loss

- rigid, no tooling marks, uniform translucency when lit dimmly

 

I believe what I’m after is some sort of acrylic sheet, like the panels used in fluorescent lighting, but I don’t have any experience with these types of materials.

Anyone have any advice?

[no_connection]

No matter how you look at it the more you diffuse the more light you are going to loose.

You could put a filter between two acrylic sheets, LEE 251 for example. But it's somewhat directional and have some bleed through but not much. Maybe two sheets separated by a space would give you decent diffuse with decent light transmission and only loose maybe a stop.

Diffuse silicon put on acrylic could work but again, you are going to loose decent amount of like.

 

The more even your light source is the less diffusion is needed to make it smooth. If you can find an older LCD TV that had back lit CFL, those had pretty good diffusion. Or if you can edge light a newer TV that would be pretty even too.

[Emanuel]

16 hours ago, no_connection said:

(...) If you can find an older LCD TV that had back lit CFL, those had pretty good diffusion. Or if you can edge light a newer TV that would be pretty even too.

They can both work out, actually do the DIY job.