220 film back - compatible with 120 film

Discussion in 'Medium Format' started by cheryl_mauldin, Jun 22, 2005.

  1. I bought a 645 with a 120 back, but was shipped a 645 with a 220
    back. I ordered three cases of film the same night. Can I use 120
    film in the 220 back and what would be the consequences?
  2. You need to tell us which camera. I know with the Hasselblad, you can use 120 in the 220 back, but you lose a frame at the end.
  3. Sorry. It is the manual focus Pentax 645.
  4. Here is a previous thread I found doing a search on this forum. Look at the last post.


    I would think that it is possible to put 120 film through a 220 back without suffering focus problems. I've done it on my Hasselblad (last frame cut in half) and on my Mamiya C330 (no bad consequences at all). However, I don't know about doing it repeatedly, as the 220 back is not designed to handle the extra thickness of the paper backing on 120 film. Up to you. If you need to shoot immediately, you can probably chance it (although, if it's a wedding, I wouldn't), but it would make me nervous, and I'd either send the rest of the film back or get a 120 back.
  5. First off, the Pentax 645 does not have interchangeable backs. It does however, have inserts. On some cameras(e.g. Contax) you can rotate the insert for the 120 or 220 film. I don't know the details of the Pentax.
  6. Hard to say. Usually the pressure plate is spring loaded so it will take the extra thickness of backing paper on 120 film. You may feel that winding is stiffer (actually on the Pentax, the motor may need to work little harder (I would not chance this on regular basis)) and you may get scratches on the film as it rubs harder against the pressure plate. You can also get softer pictures because the sharp picture is little off the film plane (but how much, I do not know).

    I'd say if you need to use the camera right N-O-W, well it's your choice. If not, I would just wait and use the camera correctly once I have correct film and correct inserts.

    Also, call the seller and ask them to solve the problem fast. If they are worth anything, they will offer you some solution (free 220 film, expedited shipping of correct part or something similar).
  7. david_henderson

    david_henderson www.photography001.com

    There's a big difference between putting 120 film through a 220 back as a one-off emergency measure and using a 220 back as a 120 back. I don't have a Pentax but you might find one or both of the following. The thicker 120 film plus backing paper will make winding increasingly stiff as you progress through the roll. Equally, its unlikely that the back will indicate the roll's finished in the usuual way and it'll be up to you to notice that you've had 15 0r 16 shots, by which time you may have taken some more "pictures" that you'll never see. Both of these things you can put up with for the odd roll. As a way of using the camera forever? I wouldn't.

    220 backs or inserts are less common than 120 for a number of reasons including the fact that only a small and diminishing no. of films are avilable in 220; it can be quite hard to find, and more care must be taken with the film. Sending the wrong insert could either be a genuine mistake or an attempt to rid themselves of something. I'd be inclined to contact the seller immediately and tell them you want the insert you actually bought sent now please.
  8. Used 120 inserts are going for more than 220 insert for the selection of film emulsions in 220 and dealer willing to stock them has decrease in numbers.

    I kept my 220 insert for my 645 for I can get almost expired emulsion cheap (1/3 of the price of the same roll in 120). It is great for pleausre shooting.

    I had loaded a roll of 120 in my 220 insert once and the motor winder seems stressed during the winding. There were no noticible flatness issue. Also the counter does not stop and wind to the end of roll after 15/16 exposures.

    If you have paid for the camera advertised with a 120 insert in good faith you should demand that the seller make good by shipping you a 120 insert and taking the 220 back at his expense.

    If there is no will on the seller's part partially decline part of the payment equal to the cost of you getting another 120 used insert with the creditcard company. Do not wait for ever for there is a limited number of days which you can file this claim.
  9. I have both 120 and 220 inserts and the only difference I have ever found between them is a small plastic part on the right side that is rectangular shaped except for a tiny extension on one end. This plastic part seems to communicate to the camera to cutoff after 15 frames on 120 and go to 30 frames on 220. Dan Witcliff, manager of Collier's Photo here in Fayetteville, AR and who had another Pentax 645 assured me that a Pentax repairman had told him the only difference between the 120 and 220 inserts was this small plastic part. To test his theory I reversed the part in the 220 back and got the camera to cutoff after 15 frames. I also reversed it on the 120 back and got 30 frames on 220. I looked at the slides under a 8x loupe and saw no difference in sharpness. In my opinion its safe and you can pick up 220 inserts at less money.
  10. Steven wrote: I have both 120 and 220 inserts and the only difference I have ever found between them is a small plastic part on the right side that is rectangular shaped except for a tiny extension on one end.

    Correct, we found out the same yesterday and tried it out too.
  11. Hi Steven and Willie ...

    Hmmmmm ... both of you must have much better eyes than I do. I've looked at my 220 and 120 inserts and can't seem to find this "small rectangular shaped part with a small extension" anywhere. Can you be more specific as to where I can look?

    I have three 220 backs and one 120 back. I use the 220 backs regularly during wedding shoots but it would be great to "convert" the 120 back to 220 for weddings. I originally purchased the 120 back for experimenting with new lenses, film, flashes, poses, etc ...

    Thank you.

  12. Ok, take out your 120 back and look at the two silver metal tongs that you have to flip up to replace the film in the insert. This small plastic part is located directly in between these two tongs. Also, this part is located under the chrome metal catch that holds the insert in the camera. Now on the 120 back you may have a hard time seeing the plastic extension because its pointed away from the film plane and too the back of the insert. Now it is possible that your camera doesn't have this part but I doubt it. In that case you'll need to send it to Pentax Colorado. Good luck.
  13. Hi Steven ...

    Thanks my friend, finally found that illusive little part. I'll definitely give it shot and now I have four 220 backs for weddings. TERRIFIC !!

  14. "Now on the 120 back you may have a hard time seeing the plastic extension because its pointed away from the film plane and too the back of the insert."

    I looked on my 120 back, the little prong is pointed towards the film plane and cuts off after 16 exposures. I use it on the manual 645. Would mine be different for some reason?
  15. "manual focus"
  16. Hello, I have just bought a used Pentax 645N. It also arrived with 220 magazine. I had a look at that little plastic rectangle. It indeed has a small "teeth" but it was pointing inwards. So I have put one 120 films quickly through the camera, but the camera went up to about 20 shots until the film was rewound and the display showed "E". So then I remounted the little plastic thing such that the teeth points towards the film plane (or towards the shutter). One more film through the camera. After 16 shots the camera wound the film and showed "End" on the display.
    I will have to see that the focus comes out properly, but I do not expect problems as the film pressure plate has more than 1 mm of spring loaded "play" so it should easily accommodate a fraction of mm thick paper backing.
  17. I too have a spare 220 back that I might rather shoot with 120, so I just flipped the tabbed plastic piece around to give this a try with my P645N. Easy one minute job.
    The one thing that might be different and not as obvious at first glance is the between-frame spacing, i.e. the relatively thinner diameter spooling for the first 16 frames of the 220 roll might have required a different ratio gearing than the 120 inserts to keep the spacing the same. Anybody looked at this and measured it on their finished rolls of 120 yet? I wouldn't care if it's wider on 120 on the 220 insert than with a proper 120 insert. Crammed closer together would be more of a problem when cutting strips apart for insertion in to sleeves or cutting individual frames out for drum scanning.

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