Diffusion material for softbox

Kashim · Post by **Kashim** » Wed Mar 09, 2016 7:31 pm

Hi. I'm looking for some advice about diffusion material for my softbox. I've tried a few different things like styrofoam, printer paper, paper towel, etc. and finally settled on tracing paper. Right now I'm using 2 layers of tracing paper to diffuse my flash. My softbox is about 2.5" deep and the front surface is 5" x 8" and there's a layer of tracing paper about 1" from the flash surface and another layer at the front of the softbox. I work with live subjects only, mostly jumping spiders. My subjects are usually between 3mm and 20mm and I'm using 1x-1.5x magnification most of the time.

I'm getting pretty decent results with my current setup, but of course I'm always looking for something better. The tracing paper I'm using is the cheapest I could find at Staples and I noticed its translucency is not exactly uniform if I shine a light through it. There are two other materials I've been meaning to test out, but they're much more expensive than tracing paper. One is vellum paper and the other is white nylon specifically for diffusion. I'm hoping someone here has experience with all three (tracing paper, vellum, and nylon) and can tell me if I would see much difference switching to either material.

I looked at the vellum paper at Staples and it seems thicker and much higher quality than the cheap tracing paper I'm using now. Its translucency seems much more uniform than the tracing paper's as well.

This is the one I was looking at:
http://www.staples.ca/en/Gartner-Studio ... CA_1_20001

The white nylon I'm considering is from Amazon and I can't look at that until I actually order it. The description says Nylon Silk White Seamless Diffusion Fabric for Photography Softbox, which sounds pretty good.

This is what the white nylon looks like:
https://www.amazon.ca/Neewer-Seamless-D ... _pC_nS_ttl

I love trying new stuff, but I'd rather not waste money on these things if I won't see any difference compared to the tracing paper I'm using now. So any advice about this could save me money and would be much appreciated.

Lou Jost · Post by **Lou Jost** » Wed Mar 09, 2016 8:58 pm

I am a painter of nature and got some vellum a few years ago for that. I never thought to use it for a diffusing material but it might work well. It is not as transparent as tracing paper, so it will diffuse more. It is also very uniform, and it has a microscopically rough surface. But I bet you'd get very similar results just using a double thickness of tracing paper instead of one, for each layer.

Chris S. · Post by **Chris S.** » Wed Mar 09, 2016 11:19 pm

Kashim,

Your link to a vellum paper at Staples doesn't work on my browser. Like you, I've been interested in trying vellum as a diffusion material. But as we know, true vellum is a kind of leather. I have serious doubts that most so-called "vellum papers" will truly resemble vellum as diffusors.

While not the same as the nylon you asked about, I have a stock of white ripstop nylon from Jo-Ann Fabrics, which I find useful in making the light output of my (cheap) soft-boxes more even. These softboxes are larger than yours, having a couple square feet of illuminated area. I've found that by adding a layer or two of this white nylon to the front of the softbox, I get a much more even light distribution.

None of this directly addresses your questions. But perhaps it may of some use anyway.

Cheers,

--Chris

johan · Post by **johan** » Thu Mar 10, 2016 12:41 am

I've tested these 3 against each other. Lou is right, vellum is very similar to a couple of sheets of tracing paper together. With nylon, I got a definite hotspot - so it's too thin and doesn't scatter enough. Some more comparisons at http://extreme-macro.co.uk/macro-diffusers/ - bottom of page

Beatsy · Post by **Beatsy** » Thu Mar 10, 2016 4:12 am

If you can get hold of an old (broken) LCD monitor, they contain some really useful sheet materials. Just yank off the bezel and pull the various layers of the screen apart. There's a sheet of polariser and, in relation to the current topic, a sheet of plastic diffuser material. I lost my piece, so I never really investigated it's workings in depth, but it provides excellent diffusion without cutting much light. I guess it's for diffusing the backlight, so it has to create a very wide spread of light over a very short distance. Ideal.

Kashim · Post by **Kashim** » Thu Mar 10, 2016 11:06 am

Chris S. wrote:Like you, I've been interested in trying vellum as a diffusion material. But as we know, true vellum is a kind of leather. I have serious doubts that most so-called "vellum papers" will truly resemble vellum as diffusors.

I don't expect this vellum paper to be anything like real vellum of course. I think the real stuff is much much more expensive. I was just hoping that it would be a step up from just plain tracing paper.

johan wrote:I've tested these 3 against each other. Lou is right, vellum is very similar to a couple of sheets of tracing paper together. With nylon, I got a definite hotspot - so it's too thin and doesn't scatter enough.

Did you use a baffle for either the vellum or the nylon? If I use a single sheet of tracing paper it scatters the light pretty well, but I get a nasty hotspot. But if I add a second sheet half way down the softbox then I get no hotspot at all. I was thinking of trying the same thing with vellum or nylon. Or perhaps using a sheet of tracing paper as the baffle and then either vellum or nylon as the front surface of the softbox. Have you tried anything like that?

Nice site by the way, I've seen it before and looked at most of the info you have on there.

Beatsy wrote:If you can get hold of an old (broken) LCD monitor, they contain some really useful sheet materials.

Thanks for the idea. I don't have access to a broken LCD right now, but we do have 6 LCD monitors (all 24-32" screens) in this house, so one is bound to eventually break. It might take years though. I'll try asking around to see if anyone I know has a broken one.

TheLostVertex · Post by **TheLostVertex** » Thu Mar 10, 2016 12:56 pm

Beatsy wrote:If you can get hold of an old (broken) LCD monitor, they contain some really useful sheet materials...

So far this is the best diffusion material I have come across. The last monitor I salvaged from had 3 different diffusers in it. One plastic sheet which was frosted, no big deal really. Then it had two sheets of plastic that spread the light out some what like a fresnel lens. One sheet spreads the light out vertically and one sheet spreads it out horizontally. When I was testing it, it took a small point on light in the center, and replicated the light 4 times around it. So it was something like this (where + is the original source and - are the replicants),

- -
+
- -

(The forum software seems to remove extra white spaces out of my ascii diagram. So I hope you get the idea.)

Unfortunately, I melted much of the material I have with the modeling light on one of my flashes. So its not very heat resistant

I am not sure what the material is named, but I think they are called lenticular diffusers.

Kashim · Post by **Kashim** » Thu Mar 10, 2016 2:35 pm

TheLostVertex wrote:I am not sure what the material is named, but I think they are called lenticular diffusers.

Wow, that sounds pretty cool. Which layers of diffusing materials did you use? Did you use all three layers? Did you have to use a baffle or was it hotspot free just from the LCD material?

Compared to stuff like paper towel or tracing paper how much of the light does it eat?

wayupnorth · Post by **wayupnorth** » Thu Mar 10, 2016 3:17 pm

I used lightbox diffuser sheet for a cine transfer project a few years ago. Fairly cheap and different thicknesses, just search eBay.

Beatsy · Post by **Beatsy** » Thu Mar 10, 2016 5:42 pm

Compared to stuff like paper towel or tracing paper how much of the light does it eat?

not much

g4lab · Post by **g4lab** » Thu Mar 10, 2016 5:55 pm

Beatsy's idea is a really good one. There are zillions of dead LCD screens all over the place. You can get them at your friendly electronics recycling facilty where they will be happy to help you extract the numerous interesting materials contained in screens. probably for free.
I think many of the LCD screen films have holographically embossed microlenses in them.

Definitely worth a look!

Beatsy · Post by **Beatsy** » Thu Mar 10, 2016 6:07 pm

g4lab wrote:...have holographically embossed microlenses in them.

Definitely worth a look!

Thanks - that's what I was getting at (but not very clearly)

Charles Krebs · Post by **Charles Krebs** » Thu Mar 10, 2016 6:36 pm

My softbox is about 2.5" deep and the front surface is 5" x 8" and there's a layer of tracing paper about 1" from the flash surface and another layer at the front of the softbox.

The computer screen materials are interesting, worth investigation if you have access. If budget is super tight, then other "found" materials can work well. Nice paper is rarely free, so why not investigate the Lee or Rosco materials made specifically for diffusing lights in photography. They are also available as 21x24" sheets, typically for about $5-7 a sheet. Full 48" rolls are far more material than needed, but if you live near a professional photo store with a lighting department it is not unusual to be able to purchase the 48" roll material by the foot. See for example:
http://www.glazerscamera.com/lighting-s ... s-supplies

I live close enough to this store to drop by and get some when I need it. At $7 per foot (48" length) it goes a long way, and is an excellent, tough material, available in a variety of diffusion "densities". See:
http://www.leefilters.com/lighting/diffusion-list.html

Kashim · Post by **Kashim** » Thu Mar 10, 2016 7:25 pm

Charles Krebs wrote:The computer screen materials are interesting, worth investigation if you have access.

Thanks for the suggestions. We don't have more than a few professional photo stores around here, but I'll ask them about diffusion materials the next time I'm there.

Finding a dead LCD turned out to be much easier than I expected. I put an ad on Kijiji offering $5 for a dead LCD and an hour later already had a response. I picked up the monitor earlier and already removed the diffusion material from under the screen.

There were 2 layers of it under the screen and both sheets look the same to the naked eye, although there might be a difference at the microscopic level. The stuff kind of reminds me of those frosted report covers you can buy at any school supply store, although this stuff looks much higher quality.

I think I'll keep the two layers together like they were inside the LCD and try it without a baffle first. I'll probably need a baffle though, the stuff doesn't look opaque enough to eliminate hotspots. Hopefully I'll have some time next week to play around with this new material!

[edit] I just went back to my Kijiji ad and 2 other people replied with offers of dead LCDs. One of them even offered it to me for free. Kijiji might be an easy way to obtain this material if anyone else is looking to test it out.

g4lab · Post by **g4lab** » Fri Mar 11, 2016 2:06 am

There are so many screens around that they come to you even if you don't want them. And they end up being crushed so it is very blameless to take a few things from them before they are grounded into recycling plastic and heaven only knows what else.

I have in my collection of junk two white plastic reflectors that have cold cathode flourescent tubes in them. I thought that that might be an interesting source. But now it doesn't evern pay to round up a power supply for them because LED lighting panels are practically free from China.

When I was disassembling an LCD not long ago I noticed that the actual screen, looks like a dark surface and is especially non reflective. So I put it in with my pile of squares of smoked glass. For when you don't want the bottom reflection. I don't know whether it will work but it is really a flat matte and dark surface.