I have several A24 magazines for my old V series Hasselblad and a Mamiya ProS back which take 220 roll film. But guess what? Nobody makes 220 rolls any more. I wrote a post on using 120 size rolls in the A24 backs a while back, well here’s another use for those 220-size magazines: 35mm film! If you don’t own a Hasselblad or Mamiya RB67 it’s still worth reading this post as the principles apply to any camera capable of taking 220 film.
Aspect ratio and orientation
At the end of the process you will end up with 24 exposures on a full length of 35mm film for the 6×6 format or 20 frames for the 6×7. Each frame is the same length as a normal 6×6 or 6×7 frame (56mm and 67mm respectively) and the full width of the 35mm film. The sides will have perforations of course so the effective width of the film will be 24mm. This gives an aspect ratio of 2.3:1 or 2.8:1. The film runs vertically from bottom to top in a Hasselblad so the image frame is vertical when looking down into a waist level finder. To get a horizontal frame you have to tilt the camera on its side. The Mamiya RB67 film runs horizontally so you’ll get a horizontal frame (and an aspect ratio of around 2.8:1 with the 7cm width, but fewer exposures).
Comparing the lengths of film for 220-size and 35mm 36 exposure gives approximately 1.6m and 1.5m respectively. remarkably similar lengths. And what about the diameters? A 120 spool is 25.1mm and a 35mm cassette is 25.1mm (not including the light trap, which sticks out a few millimetres). Wow, almost like it was intentional. A quick search of the Internet showed that the 3D printing community had produced adaptors for running 35mm film through rollfilm cameras and since I have a 3D printer I printed several of the open source designs. Unfortunately these didn’t fit my Hasselblad A24 magazines nor the 35mm reloadable cassettes I have, and they wouldn’t advance the frame counter in the RB67 ProS back so I set about redesigning them so that they would work in a more universal way.
Great. Now I have a set of adaptors that would let me load 35mm cassettes into my A24 and ProS backs. The next issue to overcome is the amount of film wound on to the takeup spool before the camera is ready to take its first exposure: it can be upto 0.5m. With 120 film the initial wind-in is mostly paper backing but with a 35mm cassette the wind-in is all film and this is wasted, leaving only 1m in the cassette to be exposed. This only allows about 16 exposures in the A24 magazines before the film is fully wound out of the cassette. That’s not very economical. What’s needed is a blank leader added to the front of the 35mm film. I cut a piece of clear Mylar film but it would be possible to use an offcut of 35mm film about 450mm long. The overall length of this strip isn’t critical, what’s important is the amount wound back into the cassette, which none for the RB67 ProS and 200mm for the Hasselblad A24. This leader is taped to the front of the film protruding from the cassette then wound back into the cassette as necessaary. By doing this I get 24 exposures from a 35mm film without wasting film on 6×6 and 20 exposures on 6×7 with a little film left over. I found the best tape to use is clear pressure sensitive tape by 3M; it’s nice and thin so doesn’t get caught going through the cassette’s felt light trap and it peels off cleanly when loading the film in a tank.
Film loading for processing
The last problem to overcome depends on how you load your film for processing. I have both daylight loading and darkbag loading tanks so I thought I’d make a system for both. If you use a daylight loading tank and don’t have a darkbag you need to be able to open the A24 film magazine in daylight. You can’t do this unless the film is wound into another cassette, so you’ll need a supply of empty re-loadable re-usable 35mm cassettes. But before you rush to buy them, it’s my experience that using them adds significantly to the friction in the film wind-on mechanism. Although the Hasselblad is a robust camera they are getting old and I feel uncomfortable applying this extra force to my equipment, so yes, it can be done but I would advise against it. My preference is to load to an adapted 120 spool and unload the magazine in darkness. You may be forced to wind into a re-loadable cassette if you don’t have a darkbag or if you want to expose more films than you have magazines (or if your camera only takes one film at a time). In this case you’ll need two pairs of cassette adaptors instead of one pair plus spool spacers.
Loading the film from an adapted 120 spool into a processing tank is the same as a normal 35mm film except for two things: it’s not in a cassette so expect the film to spring off the 120 spool when you take the tension off, and remember to separate the leader so you don’t wind it into the tank with the exposed film.
What other cameras are likely to work?
Here’s a list of cameras that can take 220 size film, either via a discrete back like the Hasselblad, or by flicking a switch:
Hasselblad V series with A24 back*
Asahi Pentax 6×7
Mamiya 645 with 220 film insert
Mamiya 645AF with 220 back
Mamiya C220 C330
Mamiya RB67 with ProS 220 back*
Goodman Zone and Axis (since these take the Mamiya ProS backs)*
Mamiya GX680 with 220 back
Fuji GSW680 GSW670 GSW690
Voigtlander Bessa III (aka Fujifilm GF670 in Japan)
Rolleiflex SL66 with switch on film backs
*These I known to work with adaptors
You cannot use a camera that relies on a small red window to position the film using numbers printed on the film backing paper: there’s no backing paper and the window would need to be taped off to prevent the the film being exposed.
Where to get the adaptor set
If you have a 3D printer you can download the print file for Hasselblad at Prusaprinters.org and print your own. There are also other designs on thingiverse. The design is free for personal use under Creative Commons BY-NC-SA. If you don’t have a 3D printer you can buy the 3D printed parts from me via eBay which I guarantee will work with Hasselblad A24 and Mamiya ProS 220 magazines.