Diffusion Solved?

Images taken in a controlled environment or with a posed subject. All subject types.

Moderators: rjlittlefield, ChrisR, Chris S., Pau

Deanimator
Posts: 870
Joined: Tue Oct 23, 2012 7:01 pm
Location: North Olmsted, Ohio, U.S.A.

Diffusion Solved?

Post by Deanimator »

I think I've finally gotten my diffusion issues under control.

I went back to my PVC and packing sheet diffuser that I use for guns and other still life's. I made it narrower and used four layers of Office Max foam packing sheets for diffusion.

Image

MarkSturtevant
Posts: 1946
Joined: Sat Nov 21, 2015 6:52 pm
Location: Michigan, U.S.A.
Contact:

Post by MarkSturtevant »

Looks good!
Mark Sturtevant
Dept. of Still Waters

Lou Jost
Posts: 5943
Joined: Fri Sep 04, 2015 7:03 am
Location: Ecuador
Contact:

Post by Lou Jost »

Good, but there are still residual sparkles on narrow ridges....

MarkSturtevant
Posts: 1946
Joined: Sat Nov 21, 2015 6:52 pm
Location: Michigan, U.S.A.
Contact:

Post by MarkSturtevant »

I am curious to see what this diffuser looks like. I have similar materials laying around and I am always trying to develop a 'new and improved diffuser'.
Mark Sturtevant
Dept. of Still Waters

Deanimator
Posts: 870
Joined: Tue Oct 23, 2012 7:01 pm
Location: North Olmsted, Ohio, U.S.A.

Post by Deanimator »

Lou Jost wrote:Good, but there are still residual sparkles on narrow ridges....
True, but it's still a VAST improvement.

That was actually the product of VERY brief work between getting up and having to go to work.

Now that the basic concept has been validated, I can fine tune it by adding additional diffusion material and or repositioning the Jansjos. I haven't even tried with the flashes yet.

I need to make it a little narrower still in order to comfortably fit between the t-channels in which my magic arms are mounted. It could probably stand to be slightly shorter lengthwise in order to fit better on the cutting board mount, especially at lower magnifications and longer camera to subject distances.

Deanimator
Posts: 870
Joined: Tue Oct 23, 2012 7:01 pm
Location: North Olmsted, Ohio, U.S.A.

Post by Deanimator »

MarkSturtevant wrote:I am curious to see what this diffuser looks like. I have similar materials laying around and I am always trying to develop a 'new and improved diffuser'.
I'll try to post a picture by Sunday.

It's based on a design I got from a gun collector's forum I'm on. Gun forums always have lots of gun pictures, and guns are almost invariably shiny and require diffusion, at least when shot in the studio.

It's similar to the portable fabric hangars they used during WWI to work on aircraft where there were no permanent facilities, like Russia. The diffuser is the "hanger", and the camera and subject stage are the "airplane", only I move the hangar over the plane, not the plane into the hanger.

Since it's unglued PVC, it's endlessly reconfigurable merely by changing the lengths of the 1/2" tubes or the angles of the legs (if you use street elbows and not fixed ones).
Last edited by Deanimator on Thu Jan 18, 2018 2:50 pm, edited 1 time in total.

johan
Posts: 1005
Joined: Tue Sep 06, 2011 7:39 am
Contact:

Post by johan »

Great stuff!
My extreme-macro.co.uk site, a learning site. Your comments and input there would be gratefully appreciated.

Deanimator
Posts: 870
Joined: Tue Oct 23, 2012 7:01 pm
Location: North Olmsted, Ohio, U.S.A.

Post by Deanimator »

Here's a crop of a cuff link, one of my harder subjects.

It's cropped only because I messed up the focus on the right side.

It could probably use a bit more diffusion or moving the lamps away a little more.

Image

ChrisR
Site Admin
Posts: 8668
Joined: Sat Mar 14, 2009 3:58 am
Location: Near London, UK

Post by ChrisR »

All the packing materials I've considered as diffusers, haven't been very good.
Looking through them at a bright light, there's always been a hot spot in line with the light.
Paper, either normal office, or tissue, is good.
Cooking/drawing translucent papers are stiffer.
The stationery shop man is now used to me rifling through his stock and holding file covers and folders up to stare through them at a bright light :smt104
Some are good enough to stand over the subject as a tent.

Having a gap between the layers helps a lot, too.
Chris R

Deanimator
Posts: 870
Joined: Tue Oct 23, 2012 7:01 pm
Location: North Olmsted, Ohio, U.S.A.

Post by Deanimator »

ChrisR wrote:All the packing materials I've considered as diffusers, haven't been very good.
Looking through them at a bright light, there's always been a hot spot in line with the light.
Paper, either normal office, or tissue, is good.
Cooking/drawing translucent papers are stiffer.
The stationery shop man is now used to me rifling through his stock and holding file covers and folders up to stare through them at a bright light :smt104
Some are good enough to stand over the subject as a tent.

Having a gap between the layers helps a lot, too.
A while back, I bought a bunch of stuff as potential diffusion media.

I've also got some tracing paper I can try.

mawyatt
Posts: 2497
Joined: Thu Aug 22, 2013 6:54 pm
Location: Clearwater, Florida

Post by mawyatt »

The translucent stuff that's on the cheap eBay light tents works well. These small tents are just $10~15 and work well. I just remove the velcro side and set the tents over the entire subject and mounting fixture, then a slit that I cut on one side allows the camera lens to poke thru inside the tent.

Best,

Mike
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike

MarkSturtevant
Posts: 1946
Joined: Sat Nov 21, 2015 6:52 pm
Location: Michigan, U.S.A.
Contact:

Post by MarkSturtevant »

ChrisR wrote:Looking through them at a bright light, there's always been a hot spot in line with the light.
Paper, either normal office, or tissue, is good.
Cooking/drawing translucent papers are stiffer.
The stationery shop man is now used to me rifling through his stock and holding file covers and folders up to stare through them at a bright light :smt104
Some are good enough to stand over the subject as a tent.
Having a gap between the layers helps a lot, too.
I too am always riffling through the recycling bin at work, and skulking in stores for diffuser materials. I am sure I have gotten strange looks by holding up translucent notebooks to the light, and taking pictures of cheap plastic light globes (some of those are potentially good diffusers) :)
As for a hot spot, it seems to me that as was said you can directly block or attenuate light that would make a hot spot. I have blocked it by using my left hand over that area. I also sometimes tape on something that is handy like a leaf over the spot. This has helped but not always. Attenuating the hot spot is by adding additional layers of material over it. Right now my current favored diffuser (a big piece of transluscent plastic milk jug) has a few layers of white tracing paper over the hot spot area. It definitely helps. And I can then add more by blocking as described above.
Mark Sturtevant
Dept. of Still Waters

mawyatt
Posts: 2497
Joined: Thu Aug 22, 2013 6:54 pm
Location: Clearwater, Florida

Post by mawyatt »

One of the advantages of using multiple light sources is you can blend the sources with diffusion and help reduce bright spots. Also, you can control the output of the various sources and create intensity gradients for specific effects.

Best,

Mike
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike

Deanimator
Posts: 870
Joined: Tue Oct 23, 2012 7:01 pm
Location: North Olmsted, Ohio, U.S.A.

Post by Deanimator »

Right now, I'm doing a 205(?) image stack of the same cuff link.

I added another double thickness of packing sheet, for a total of eight layers.

I won't be able to try any other modifications until I'm off on Sunday, and then probably not until late in the day.

Deanimator
Posts: 870
Joined: Tue Oct 23, 2012 7:01 pm
Location: North Olmsted, Ohio, U.S.A.

Post by Deanimator »

With eight layers of diffusion and better focus. The framing could be a bit better:

Image

Post Reply Previous topicNext topic