70mm hasselblad back - 35mm conversion?

chrism · Jan 18, 2010

I've heard it's possible to convert a 70mm hasselblad back to shoot 35mm film. 70mm backs are pretty darn cheap. I've no desire to shoot 70mm film (too many film formats as it is). Does anyone know anything about this conversion? What is required? I can't find any information on this and I have scoured numerous sites.

keithwms · Jan 18, 2010

It is easy. Take a 120 spool, cut it in half, file it down a bit, and put it into the 35mm canister. Like thus:

Further details may be found (there was a url link here which no longer exists).

AgX · Jan 18, 2010

keithwms,

Your link is restricted to Apug subscribers (at least this is the content of the message I receive).

keithwms · Jan 18, 2010

Sorry, I don't know where I stored the hard link. Let's see...

Okay I put it on my site: http://keithwilliamsphoto.net/Spool120_135.jpg

I'll just expand on what I wrote earlier in a PM and note that I have done this with various cameras, using 645, 6x7, 6x8, 6x9, and 612 backs, and had no big problems. I do not recommend doing it with an autowinding back though, not sure if that applies here.

If you wanted to make it more elaborate, you could put another 35 container on the takeup spool and gather the film into that. My simpler way of doing it requires unloading the film in the dark.

chrism · Jan 18, 2010

Does this work on the 70mm back though? It's different than the 120 back and has a sprocket advance.

keithwms · Jan 18, 2010

Oh, sorry, I glossed right over that :rolleyes: Well let's see then, I guess you need a way to rig the takeup spool to grab the film. What does your takeup spool look like?

chrism · Jan 18, 2010

keithwms said:
Oh, sorry, I glossed right over that :rolleyes: Well let's see then, I guess you need a way to rig the takeup spool to grab the film. What does your takeup spool look like?

I don't actually have the back, I don't want to buy one until I know if I can mod it. I know it's possible but I just wanted to see if anyone has done it here and what is required.

70mm film is loaded in cartridges that look like oversized 35mm cartridges.

keithwms · Jan 18, 2010

I have a 70mm cartridge here with me, it looks like you just need a clip or something to attach the end of the 35mm film to the spool.

Q.G. · Jan 19, 2010

The Hasselblad 70 mm back has a 'feeler', a lever that is pushed down by film, pops up when there isn't any film to keep it down, and then locks the mechanism.
The lever is to one side, and unless you can put the 35 mm over to that side far enough, you will need to tape it down.

The counter and spacing mechanism are driven by a sprocket wheel, engaging the film's perforation. I don't know how to get round that in a hurry.

70mm hasselblad back - 35mm conversion?

Privacy & Transparency

Privacy & Transparency