Just crop the perforations out. You only want to cut the film on one side anyway. Your aspect ratio may be more like 6x9 or a 35mm frame in the end. Nothing wrong with that.
Originally Posted by polyglot
If it were me (with my Horseman 6x9 system) I'd take the rool of 70mm and use a fine cut saw to cut the perforations off one end of the roll. How much? Well, you have the spools, just cut it to fit your spools. Then I'd just load it on the spools in the dark. How much film? I'd just fill the spool to the brim and keep them in the dark, like sheet film. The Horseman 220 backs are cheap now, so I'd get maybe 5 of them and just load them in the dark. Loading each back can't be any harder then loading 8 film holders in the dark. No leader paper, just attach the film to the spools in the dark with some tape. Since you are in the dark, as soon as you close the back you are 'good to go,' no need to look for a 'wind-up' mark before closing the back.
When ready to process, load frame #1 on the reel first and run it to the center and just cut off any excess. No fancy measuring is needed for any of this unless you wind up with frame spacing issues (depending on how your back works). In that case a little trial and error to find out how much 'wind-on' is needed for the start of the roll before closing the back, or build up the take up reels with some tape to the desired starting diameter and just close the back after taping the film on the take-up spool.
If you are perfectionist and want the lens centered, you can measure how much the perorations extend into the image area, divide that by two and apply that much front rise, on a Horseman (load the perforations to the bottom of the frame). On the RZ load the perforations on the top and you get a little automatic 'front rise' for each image after you crop.
Last edited by ic-racer; 11-22-2012 at 08:38 PM. Click to view previous post history.