Pentax 645 120 film doesn't rewind after 15 shots

jmacy9109

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Just bought used pretty good condition pentax 645. First roll I shot it the film rewinded no problem. But the rest ive shot since It doesn't rewind and I've just had to click the shutter another 15-20 times and then I can take the back out with and it is wound up. It never does any rewinding though. Also when I try to do the manual rewind with the screw from the bottom that doesnt seem to work either it just keeps going and going (ive done it for along time) and film is still exposed. The only thing that works is firing the shutter off a dozen or more so times after 15 then it is wound up. I am using brand new batteries to seen alot of people saying things about batteries.
 

Dennis-B

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The film is not supposed to rewind. It advances on the take-up spool, and should be completely wrapped leaving the seal tab protruding. When reloading the camera, the feed spool is relocated to the take up side. You then wet the seal, keeping the exposed roll from unwinding and exposing the film to light.

In case you haven't read it, get a copy of the user manual. It gives detailed instructions for loading, advancing, and unloading the film.
 
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jmacy9109

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Ok I worded it incorrectly when i said rewind i meant advance to the take up spool. Why does the film not advance to the take up spool after taking 15 shots. I have to hit the shutter another 13 times.
 

MattKing

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Welcome to Photrio.
Is the camera set for 220 film?
 

Deleted member 88956

MattKing said:
Welcome to Photrio.
Is the camera set for 220 film?
Click to expand...
It is the back that does the 120/220 not the camera itself. There are 220 backs on the market that had been hacked to tell camera it is a 120, except the film pressure plate still being the wrong type. I can't think of any reason to hack a 120 to make it act as a 220 though, but possible all the same, same trick.
 

pentaxuser

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I believe that what Matt meant in his question Is it a a 220 back that is still set to 220? In Pentax inserts there is a way to alter a 220 back to act as if it was 120 but unless the user knows what he is looking for the change in setting is not obvious. Had I just received a new-to-me P645 I might have expected it to wind on after 15 shots. However I admit that if the OP has a 220 back that is still set for 220 then why did it successfully wind to the end the first time when he only fired 15 times?

It just seems strange that that another 15 shutter operations successfully completes the wind-on.

pentaxuser
 

MattKing

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I probably should have worded the question as: "Is the camera set up for 220".?
I have never used any of the Pentax 645 SLRs, but my recollection was that they use film inserts.
I couldn't remember whether the inserts were switchable between 120 and 220, or whether you needed to have separate inserts for each of 120 and 220, or whether the inserts could be fudged to permit using 120 in a 220 insert.
Perhaps the Pentax 645 users here could advise the OP how to identify which type of insert is installed in his/her camera?
 

itsdoable

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pentaxuser

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MattKing said:
Perhaps the Pentax 645 users here could advise the OP how to identify which type of insert is installed in his/her camera?
Click to expand...
God point Matt and this may be the start of finding the cause or at least eliminating what is not the cause. On this site GRHazelton is very knowledgeable. I only have 120 inserts and frankly don't have access to the before and after pictures that illustrates the difference which I think GR does but I can say that when I Iast saw these pics the difference was extremely subtle.

It may help the OP to go to the Pentax forums and join it. Membership is free. He needs to look at the Medium Format section and find a very long thread on I think "conversion of 220 backs to 120" or some such title. From what I can recall there were pictures in that thread that may help

pentaxuser
 

ic-racer

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For
pentaxuser said:
Can you explain why this helps the OP with a specific wind-on problem with a P645?
Thanks

pentaxuser
Click to expand...
Pentaxuser, please correct me if I am wrong but I believe these film sensing contacts, like the Rolleiflex, need a wire (which could come lose) to make a complete circuit.
 

Deleted member 88956

ic-racer said:
For

Pentaxuser, please correct me if I am wrong but I believe these film sensing contacts, like the Rolleiflex, need a wire (which could come lose) to make a complete circuit.
View attachment 255058
Click to expand...
P645 uses purely nechanical means to tell camera which insert is in as shown in early post with pics.
 

pentaxuser

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ic-racer said:
For

Pentaxuser, please correct me if I am wrong but I believe these film sensing contacts, like the Rolleiflex, need a wire (which could come lose) to make a complete circuit.
View attachment 255058
Click to expand...
My question was about the link you provided as this seems to be about the range of good for fortune and bad fortune experienced with e-bay purchases. Was this the link you meant to provide?

Thanks

pentaxuser
 

itsdoable

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Witold said:
P645 uses purely nechanical means to tell camera which insert is in as shown in early post with pics.
Click to expand...
It's been several years since I've own a P645, but I believe there are 2 electrical contacts on the left side of the insert that tell the camera that there is film loaded, which is sensed by those feelers that stick out through the pressure plate..
 

Deleted member 88956

itsdoable said:
It's been several years since I've own a P645, but I believe there are 2 electrical contacts on the left side of the insert that tell the camera that there is film loaded, which is sensed by those feelers that stick out through the pressure plate..
Click to expand...
Not sure what those two do, but film insert has side tab to tell body 120 or 220, so with 220 it will continue to advance film by single frame past 15. As in post #6, tab can be flipped on either insert so technically either one could be used for either film. Trouble starts with pressure plate being of different thckness, but that is another story.
 

pentaxuser

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So, jmacy9109, any luck with any of our ideas? Always nice to hear if our contributions bear any fruit

pentaxuser
 

ic-racer

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pentaxuser said:
My question was about the link you provided as this seems to be about the range of good for fortune and bad fortune experienced with e-bay purchases. Was this the link you meant to provide?

Thanks

pentaxuser
Click to expand...
The thread linked was supposed to be about this repair of a Rollei 6008 film back that would not wind up after the last shot. This wire to the film sensor had come loose. After re-connecting, it has worked flawlessly.
 

ic-racer

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The Pentax 645 manual seems to indicate "B20" is the film sensor switch with wire "63" attached.
 

fs999

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ic-racer said:
The Pentax 645 manual seems to indicate "B20" is the film sensor switch with wire "63" attached.
Click to expand...
This is when loading the film I suppose, not when 15 frames have been shot.

Btw I didn't selected the right photo I had in mind. Correct is : 120 is on the left and 220 on the right.
 
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