Shooting 120 film without the paper backing?

RandyTM

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Simple question… I hope. Can I shoot 120 film without the paper backing? I have a pinhole project in mind and I would like to use 120 film but without the backing which would make it easier to load / unload the camera… I know that sounds crazy but in this particular case it would. The film would NOT need to be advanced in camera and the film would be loaded and unloaded in the dark. Related question, isn’t the old 220 format just 120 film without the paper backing?
 

koraks

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You can, with some caveats. Many 120-format cameras/backs have a window in the back that allow you to view the frame numbers printed on the backing paper. This will evidently create problems if no such paper is present. In addition, halation may be more pronounced. I doubt this is much of a concern with pinholes in particular though. The same goes for minor issues with film flatness resulting from the backing paper missing.
 

mshchem

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Film is film. As long as you load it in the dark and the pinhole is the only source of light. Not sure what the advantage is?
 

mshchem

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220 only have paper on the ends. The film is exposed with no backing paper. Paper is there to protect film while loading and unloading.
 
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RandyTM

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First TY .... OK... so if I black flock or matte black paint the film backing support structure in the camera that carries the film would that mitigate the halation issue ? Or maybe I should just attach the paper backing to the film support structure and change it every so often... Hmmm, kinda answered my own question ... lol.
 
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RandyTM

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Thanks, I will. It's going to be one of those crazy builds with the 120 film wrapping around a center core being exposed with multiple pinholes.
 

Vaughn

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Cool project! Most 120 films have an anti-halation layer that should give you a hand, along with a flat black backing.
The light coming from the multiple pinholes bouncing off the curved surface of the film -- then all around the inside the camera will be an issue to work with.
Have fun!
 
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RandyTM

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Thanks. I'm also thinking about using Ortho film on this build because it's looking like it will be a total pain trying to load pan film in complete darkness.
 

xkaes

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Whether you are scavenging a 120 back from something else or making the back yourself, it doesn't really matter. You need to figure out the exact (as possible) distance from the pinhole to the film -- and THEN figure out what size pinhole(s) you want.

Some sort of permanent paper-backing could be used to help prevent scratches on the film, but maybe you've already figured that out.
 

Vaughn

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Ah! Something like Ilford's Ortho Plus.

"Ortho Plus 120 roll film is coated on 0.125mm/5-mil acetate base and is edge
numbered 1 to 19. The base has excellent anti-halation properties"

Also very fine grain. Reminds me of my use of Kodak Tech Pan in a plastic Diana Camera! Worked great!

Carbon print below (two 1.75"sq images)...

PS...crazy thought...depending on the length you need, another possibility for film that can be handled under safelight would be x-ray film, cutting it to width and length needed. No anti-halation layer, in fact most have light-sensitive emulsions on both sides. There is some single-sided (for mammograms), but I do not know if it has an anti-halation layer. Usually on 0.007" stock, so stiff and would be processed more like sheet film.
 

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RandyTM

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I'm on the look out for something without any numbering if possible. I have ordered a test roll of "x-ray" film from photography project as a test... Well, actually I am still working through the raytracing math to see how gonzo I can actually go. I'm hoping to have a 250mm diameter core to wrap the film around but not sure the maths will work out. But my motto is that it's better to fail spectacularly than succeed safely... lol
 

MCB18

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I’m very curious to see how this turns out! And yes, as long as you handle the film in the dark it’s fine without the backing. I order long lengths of 120 film regularly to make my own rollfilm. it’s just film. A bit wider, but still film.
 
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RandyTM

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Me too! I have worked out the ray trace maths for the 120 based, 4 hole version with a 225mm diameter core wrap and a 4 X 5 based, 3 hole version with a 44 mm core wrap as a proof of concept. I have that one designed (see image attached of the enclosure design) and will 3D print it later today. With any luck I could have an image from the 4 X 5 version next week. Still wrestling with the design of the120 version. I will need to take a hybrid approach to its construction because of the size so that one is still a work in progress.
 

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RandyTM

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Here's the first light image from the 4" X 5", three hole POC camera. It worked reasonably well once I got my head around three inverse images projecting onto a single, curved film plane, lol… So I’m moving on to the four hole 120 version now. Stay tuned .
 

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Sirius Glass

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Thank you for showing your work in progress!
 
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