70mm workflow – or, how to manage when someone gives you a decade’s supply of aerial mapping film…

Almost a year ago, a very kind friend (thanks Frazer!), engaged in some sort of office cleanout, rather than throwing away several 150ft rolls of quality Kodak aerial film, thought “I wonder if Marc would like these?” – and so I became the proud new owner of this grand collection of recently out-of-date 70mm film stock, and wondered to myself… um, how do I shoot and process this?
70mm film is another motion picture industry by-product that never really took off in still photography. Nonetheless, it’s use was widespread in some niche industries, like US yearbook photography and aerial mapping – affording a compact means of taking lots of high quality film up into the air without needing to reload, or reload as often. 70mm film was also used quite a bit in space, with all the manned Apollo space missions taking along specially adapted Hasselblad EDC’s (which they LEFT on the moon!!!) that were fitted with 70mm film backs (they brought those back to Earth).
Shooting the film turns out to be easy – a couple of camera manufacturers, like Hasselblad, Mamiya, and Graflex, made 70mm film backs – the Mamiya one, originally designed for the 6×7 Mamiya RB67, fits a standard mini graflok back – so I found one and stuck it on the back of my little 2×3″ Crown Graphic, and started snapping away.
Um, hang on Marc – you’ve jumped a step or two – if this blog entry is about workflow, then we need to start with getting 150 feet of film into something a bit more useable…
So, the film comes in a box like this, and inside this box is a handsome metal tin, and inside this metal tin is (in this case) 150 feet of film – that’s an awful lot, considering a normal 120 roll is only around 3 feet, and gives you 10x 6×7 shots. Somehow we need to cut the film down into smaller rolls, for convenience…. And so we need a bulk loader – penny-pinching 35mm shooters will be well-used to these contrivances, and here the whole thing is simply “up-sized” to 70mm.
The principle is – in complete darkness (or in a dark bag/tent), you load the 150ft reel into the main chamber, and then you put an empty 70mm canister into the smaller section, wind the film into it until it’s full, and then cut the film off (there’s a handy/scary razor inside), ready for the next canister. So you end up with one of these, full of 70mm film: which I have wisely labelled to remind me (years later) what film I actually have loaded in there. And then the canister, with a friend to takeup the exposed film, are loaded into the film back, like so: One canister gives us around 50x 6x7cm negatives, which for anyone familiar with shooting medium format film, is almost more film than it is possible to know what to do with. Certainly, shooting an event where reloading is awkward or impractical, becomes immediately less silly with a medium format camera.
Here’s my Crown Graphic all ready to go, in this manner. Actually, I’ve had one canister loaded in this for the better part of a year, and am yet to run out of film…

From here on, all that remains is to shoot and shoot and shoot and shoot, until the roll is done, then load (in complete darkness) the film onto a reel:
bung the reel into an extraordinarily large processing tank (in this case, a tank designed to fit two reels, for maximum workflow efficiency):
and process the film per the manufacturer’s instructions. Which is where we can get a bit stuck, because many of these aerial emulsions are designed for processes not necessarily available to the masses – thank heavens for nice people in far flung Nevada who tell you stuff. The hot tip for this particular Plus-X emulsion (similar to the Plus-X we all know and love, but with a thicker base and some other stuff going on) is: “1 gram Dektol per 100 ml h2o, 30 sec agitation and then walk away and let it stand for 15 minutes. Perfect every time. One shot, you chuck the weak dektol after that.” Thanks Jim.
And hopefully, one day when I actually finish a roll, I’ll have some pictures to show. Using all this film may take some years, but, uh, what FUN.

4 thoughts on “70mm workflow – or, how to manage when someone gives you a decade’s supply of aerial mapping film…

  1. Astonishing !

    I didn’t know we can still find so much things designed for 70mm film today ! Where do you find all this gear ? The *bay ?

    The back attached to your Crown graphic is very elegant, and seems to be very handy, but I presume the whole thing should be a little heavy when in hands 🙂 !

    Best regards,


    1. It’s taken me over a year to find all this stuff – a bit from that auction site, and a lot from some very lovely photographers who frequent APUG.org and the Large Format Photography forums.

      The back does make the Crown Graphic heavy, but it’s all relative – once you start messing about with large cameras, then I’d actually describe the Crown as “relatively” light. And then something like an Olympus XA or a Minox 35 feels ridiculously light – almost “throwaway”… I’ve taken that Crown Graphic around Norway (with a 6×9 back) and it’s actually quite a nice handheld camera – I have some lovely 6×9 transparencies from that trip.

      Cheerio, Marc

  2. Hello Marc!

    Thanks for posting that. I am wondering if 70mm would make a great addition to my workflow (even considering buying loads of film).
    What has been the most irritating part of it?
    And what has been most fulfilling? I am also considering using it with backs on my Mamiya RB67 for weddings and events.(it looks like your crown graphic has a mamiya back?)


    1. Hi Analoguey,

      It’s been interesting to have what feels like ‘unlimited film’ sitting on the back of a camera – but on the other hand, I am so used to sheets and short rolls, it can feel a bit (annoyingly) un-ending too (although I guess there’s nothing stopping me from winding shorter rolls). Certainly I never feel bad about making an extra ‘safety shot’ of anything with 70mm film.
      Apart from that, winding the film onto spirals takes some self-training… and yes, that IS a Mamiya RB67 back on my Crown Graphic 🙂

      Cheerio, Marc

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