Question about the Pentax 6x7 MLU

[alexandru_voicu]

Hi everyone,


A few months ago, I purchased a nice Pentax 6x7 outfit. The former owner told me that the camera has never been CLA'd, so I sent it to one of the better known technicians in Europe (better known, but necessarily for repairing Pentax cameras). The whole thing turned into a bit of unpleasant and expensive adventure (having to send the camera twice), but this is secondary to the topic of this post. In short, even with the camera CLA'd, I find the rewind crank to be a little stiff. I realize that a single stroke rewind lever has to do a lot of things with a medium format film, but even so it seems a little too hard to operate. After some google searches, I found this youtube video showing how to lube a stiff film retainer (skip to minute 3:43 to see the result). I opened my 6x7 to check what I already knew: the retainer in my camera is stiff. Almost impossible to turn it with my fingertips. Even with an empty spoon loaded, there is no way I can replicate the movement in the video (in fact, I was unable to turn the empty spool even a little). So my question is: is the retainer supposed to be stiff or not? And if it's not supposed to be stiff, how serious of a problem does it represent? Any thoughts from current or former Pentax 6X7 owners will be greatly, greatly appreciated.

Given that this is my first and only 6X7 and that I cannot make a comparison, it might be that my "instincts" are plain wrong and that my camera is perfectly functional.

Regards,
Alex

 

[charjohncarter]

I have film in mine now, but I don't recall it being stiff. Do you mean when you are advancing the film?

 

[alexandru_voicu]

I have film in mine now, but I don't recall it being stiff. Do you mean when you are advancing the film?

In my camera, the tiny metal thingy (film retainer) that goes into the slots of the film spool is stiff, much like in the beginning of the video I mentioned in my first post.

As for the overall stiffness when advancing film, that is my instinct, but I must say that I've always used 35mm cameras. So, yes, I do not expect the Pentax 6x7 lever to be so smooth as my Leica M6 lever, but yet I feel it's stiffer then it "should" be. Having said this, I have no idea how it "should" be, as I don't have access to a second 6x7 body. 🙂

 

[randy stewart]

Pentax 6x7 service

Pentax 6x7 service

I hope I understood your problem correctly. The film supply spool should have some resistance so the the film is under tension as it is advanced. (Without such, the film winds too loosely on the take-up spool, leading to mid-roll jamming - a matter for another day.) With a new roll loaded, you should be able to pull out the leader/film without meeting great resistance. To me, it sounds like whoever serviced your camera did not clean and adjust the supply resistance. I have two 6x7 MLU versions. They do not resist film advance to a degree which requires force enough to raise concern. After two trips to the same repairman without getting it all right, I think you need a new repairman. Pentax used to designate authorized repair companies for their cameras. If they still do so, start there instead of "word of mouth" over the internet.

 

[alexandru_voicu]

I hope I understood your problem correctly. The film supply spool should have some resistance so the the film is under tension as it is advanced. (Without such, the film winds too loosely on the take-up spool, leading to mid-roll jamming - a matter for another day.) With a new roll loaded, you should be able to pull out the leader/film without meeting great resistance. To me, it sounds like whoever serviced your camera did not clean and adjust the supply resistance. I have two 6x7 MLU versions. They do not resist film advance to a degree which requires force enough to raise concern. After two trips to the same repairman without getting it all right, I think you need a new repairman. Pentax used to designate authorized repair companies for their cameras. If they still do so, start there instead of "word of mouth" over the internet.

Randy, thank you for taking the time to share your thoughts on the matter. Indeed, with a new roll loaded, I am able to pull out the leader of the film with some degree of resistance, but nothing to be worried about (I think). After closing the back of the camera, the film advance is relatively easy until the first frame is in position. From then on, there is noticeable tension in the advance lever until the end of the roll.

Also, I noticed that there is some uneven spacing between the frames of my first roll shot after the CLA (a few millimeters plus or minus) . There is no overlapping and all the 10 frames are well within the length of the film. But the spacing varies just a little bit from one frame to the other.

Coming back to my first post, the major question was this: can the metal film retainer (the pronged metal thingy from the top-left of the camera with the opened back) be rotated with relative ease or is it supposed to be stiff?

Many thanks and my apologies for the horrible English,
Alex

 

[gavinlg]

Randy, thank you for taking the time to share your thoughts on the matter. Indeed, with a new roll loaded, I am able to pull out the leader of the film with some degree of resistance, but nothing to be worried about (I think). After closing the back of the camera, the film advance is relatively easy until the first frame is in position. From then on, there is noticeable tension in the advance lever until the end of the roll.

Also, I noticed that there is some uneven spacing between the frames of my first roll shot after the CLA (a few millimeters plus or minus) . There is no overlapping and all the 10 frames are well within the length of the film. But the spacing varies just a little bit from one frame to the other.

Coming back to my first post, the major question was this: can the metal film retainer (the pronged metal thingy from the top-left of the camera with the opened back) be rotated with relative ease or is it supposed to be stiff?

Many thanks and my apologies for the horrible English,
Alex

Alex - I have a really nice later model 67 and have the same feeling with mine. I've only run 2 rolls through it so far but what I've found is that the film advance lever resistance does feel a bit stiff. I've also noticed from the first roll that the frame spacing is a little uneven.

If you do find out an answer, let me know what happens because I'm interested too. Once I've run the film currently in it I'll see how loose the film retainer is on my camera and report back.

 

[alexandru_voicu]

Alex - I have a really nice later model 67 and have the same feeling with mine. I've only run 2 rolls through it so far but what I've found is that the film advance lever resistance does feel a bit stiff. I've also noticed from the first roll that the frame spacing is a little uneven.

If you do find out an answer, let me know what happens because I'm interested too. Once I've run the film currently in it I'll see how loose the film retainer is on my camera and report back.

Sure, I'll let you know. However, after watching all the youtube videos showing the film loading of Pentax 6x7, I am inclined to believe that the behavior I described in my first post is rather normal. The film retainer from the top-left should be hard to turn. How hard, I'm afraid I cannot say, nor measure. Please let me know your findings, too.


Regards,
Alex

 

[leicapixie]

I think we have a language and translation problem .
It is advance lever, there is no rewind crank, knob or else.
The film runs staight line to take-up spool, right side.
I had non-MLU model but otherwise "almost" identical.
The spool should turn freely as paper and film are pulled out and attached.
Download a Instruction booklet from Pentax..

Stiffnes in Film Advance is wrong!
Mine was smooth, a camera barely used..
A potential problem of Pentax 6x7..

A stunning professional tool.
It was simply too heavy and traded it for Leica M6, at Samy's L.A.

 

[alexandru_voicu]

I think we have a language and translation problem .
It is advance lever, there is no rewind crank, knob or else.
The film runs staight line to take-up spool, right side.
I had non-MLU model but otherwise "almost" identical.
The spool should turn freely as paper and film are pulled out and attached.
Download a Instruction booklet from Pentax..

Stiffnes in Film Advance is wrong!
Mine was smooth, a camera barely used..
A potential problem of Pentax 6x7..

A stunning professional tool.
It was simply too heavy and traded it for Leica M6, at Samy's L.A.

My English is lacking in technical terms. Yes, I meant the advance lever (not rewind crank etc.). I wonder whether stiffness may also be the wrong word... Without film, the advance lever moves smoothly. With film, a lot more force is needed to turn it. Surely, that is logical, but the amount of force seems to my untrained eye a little disproportionate. And, again, I'm returning to the pronged film retainer (the metal piece that holds the film in place). In my camera, it is very hard to turn with the fingertips. Is that normal?