35mm insert for 4x5 film holder

A few weeks back, I designed a 3D printable insert to hold a cut strip of 35mm film in a 4x5 film back for wide panoramic shots. I'm not great at 3D design, so it's pretty janky but it worked well enough. It prints in 2 parts due to some conflicting overhangs, but the parts fit together and then slide into a standard 4x5 holder in the place of a sheet of film. I'm attaching a screenshot of the design as well as the first photo I took with it. The test photo has some bad light piping but that was just because it's from right after the leader of a roll of respooled Aerocolor IV. I hope a film scan is ok here - my intent is just to demonstrate the film holder itself, not any kind of hybrid processing. I'm also not sure whether to post this here or in the camera modification forum or maybe somewhere else entirely.

I spent a lot of time searching for something like this, either commercial or DIY, but couldn't find anything. Did my google-fu fail me? Is there such a thing out there? If I were more confident in my mechanical design skills I'd love to design and build a 35mm roll-film 4x5 Graflok back. It's a great cheap way to get a pretty wide format, but loading cut film in the dark is a bit tedious. If anyone is interested, I'm happy to share design files.

Edit so people don't have to dig through the thread: I have uploaded the design files here.

That's pretty cool. Would love to see the STL files

Cool idea. Bravo.

I doubt such a thing exists anywhere else. Likely anyone who wanted to do that taped the piece of film in the holder. Your solution is good because you could, at the same time, produce a viewing mask you could place on the ground glass to compose the shot. (Pieces of film taped in a film holder are a bit unreliable.)

Emily Cook said:

A few weeks back, I designed a 3D printable insert to hold a cut strip of 35mm film in a 4x5 film back for wide panoramic shots. I'm not great at 3D design, so it's pretty janky but it worked well enough. It prints in 2 parts due to some conflicting overhangs, but the parts fit together and then slide into a standard 4x5 holder in the place of a sheet of film. I'm attaching a screenshot of the design as well as the first photo I took with it. The test photo has some bad light piping but that was just because it's from right after the leader of a roll of respooled Aerocolor IV. I hope a film scan is ok here - my intent is just to demonstrate the film holder itself, not any kind of hybrid processing. I'm also not sure whether to post this here or in the camera modification forum or maybe somewhere else entirely.

I spent a lot of time searching for something like this, either commercial or DIY, but couldn't find anything. Did my google-fu fail me? Is there such a thing out there? If I were more confident in my mechanical design skills I'd love to design and build a 35mm roll-film 4x5 Graflok back. It's a great cheap way to get a pretty wide format, but loading cut film in the dark is a bit tedious. If anyone is interested, I'm happy to share design files.

Click to expand...

I'd love to get the STL files to rwlambrec@gmail.com if possible.

Great if you want to use a 35mm film that is not available in 4x5. Maybe I'll try some Ektar 25 this way.

Since there seems to be some interest, I went ahead and uploaded them to printables.com. Feel free to use, edit, whatever anyone wants. It prints in 2 parts, one of which (part B) must be flipped over to avoid needing supports.

Don_ih said:

I doubt such a thing exists anywhere else. Likely anyone who wanted to do that taped the piece of film in the holder. Your solution is good because you could, at the same time, produce a viewing mask you could place on the ground glass to compose the shot. (Pieces of film taped in a film holder are a bit unreliable.)

Click to expand...

Yeah, I was not really sure i'd be able to even reliably tape them flat and in the right spot while working in a changing bag, and this way I can get them nicely centered and control the masking of the image on the film. A ground glass mask would be pretty easy too, as you say, but since I know the image is centered and level I've just been using the grid.

Sometimes I don't grasp things at first read. Your assembly gets loaded into a film holder just like a standard piece of film? I know I've double loaded a film holder or 2 but I didn't think there was much extra room. My lack of any hands-on with 3d printing may be the failure point in my understanding. I would think printing something so thin would be highly problematic.

MTGseattle said:

Sometimes I don't grasp things at first read. Your assembly gets loaded into a film holder just like a standard piece of film? I know I've double loaded a film holder or 2 but I didn't think there was much extra room. My lack of any hands-on with 3d printing may be the failure point in my understanding. I would think printing something so thin would be highly problematic.

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Yeah, that's exactly right, it slips in where the film normally goes. There's a photo on the linked page. There's a couple millimeters of clearance across the image area, excluding the rails on the side that hold the film flat. So this part has a total thickness of 1.5 mm except for the tabs along the edges where the film slips under the guide rails on the sides and under the hinged cover on the bottom. Those areas are quite thin indeed - 0.3 mm. But it ends up strong enough since they aren't under any significant stress.

3D printing isn't always able to handle very fine features, but even a pretty cheap printer can usually control the thickness well since it operates by squeezing molten plastic out of a nozzle. The printer can raise and lower the nozzle quite precisely, so the height at least will usually be consistent and finely adjustable. Side-to-side size can also be tuned pretty accurately but it takes more work from the operator to get there. The main challenge printing this part is just that printers aren't always calibrated to the same tolerance, and I suspect differences in film holders will also come into play. I've only tested in a Lisco Regal II. Anyone else printing it may need to play with the dimensions a bit to make it fit in their holders.

Thank you for the detailed reply. This is a cool item btw.

Take a look at a Graphic RH50 70mm roll film holder, it'll give a starting point. It uses two 70mm film cartridges that are very similar to a 35mm cartridge.
You might be able to make spacers to hold 35mm cartridges and mount it to your 35mm insert. Looks like you could get a 24mm x 120mm image on an RH50.
I have one of these RH50s if you need some photos.
Good luck and keep us posted!
Here's a link to where you can get the RH50 manual and parts list:

Bob Merlin said:

Take a look at a Graphic RH50 70mm roll film holder, it'll give a starting point. It uses two 70mm film cartridges that are very similar to a 35mm cartridge.

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Thanks, that looks promising!

I’ve also experimented with 35mm in my RZ67’s 220 back. That worked pretty well, aside from the slight inconvenience of having to use a changing bag to unload. Of course, most large format backs for 60mm film need backing paper since they use manual advance with index windows. The 70mm option looks like a good step in the right direction. It probably wouldn’t even be too tough to design whole 35mm cartridges for it and respool 35mm onto them, so all the light-sensitive prep work for multiple rolls can be done in advance.

An adapter to use 35mm in an rh50 would be a great idea

Another thought: Mamiya probably have some 35mm backs, and their backs are sometimes compatible with Graflok, so maybe there is some combination out there for 35mm on a 4x5 Graflok camera?

Oh this is exactly my kind of cursed Gonna print one when I get home, seems like a great candidate to use with the 65mm.

Another idea: you get a 6x9 roll film holder (like Graflex RH-8) for 4x5 Graflok, and use 135 to 120 adapters in the roll film holder. Then you will probably get 24x84 panoramic frames on 135 film. Two things to fine-tune:

- Adding a 24x84 film gate mask. and maybe adjust pressure plate
- check if the frame counter is still accurate for enough frame spacing, now that there is no more backing paper