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  1. #1

    Join Date
    Mar 2012
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    Pentax Super Takumar 50mm 1.4 does not focus to infinity

    I have it mounted on Spotmatic F. The "infinity" on the lens is at about 10 meters when looking through the viewfinder. I have other M42 lenses mounted on the same camera and they focus to infinity or even slightly past it, but this Super Takumar does not reach the infinity. I was mainly shooting at shorter distances (portrait) in the past with this lens, so I did not notice this issue. And at short distances the focus (on negatives) was accurate, but yesterday I tried to take some landscape pictures and noticed this issue. I did not develop the film yet, so not sure how this will look on the negative, nevertheless - what could be an issue?

  2. #2

    Join Date
    Sep 2006
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    You have forced the lens past the stop is the most likely. If the symptoms get worse then Id recommend a service.

    Won't make any difference to photos normally.

  3. #3

    Join Date
    Oct 2013
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    My guess; The lens was taken apart in the past, and the focus helicoil wasn't put back on properly.

  4. #4

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    Apr 2004
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    Or, the most common is loose set screws in the focusing ring.
    To fix it, set focus to infinity, loosen the screws a bit and set the ring so it lines up. Tighten the screws.
    Heavily sedated for your protection.

  5. #5

    Join Date
    Jun 2011
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    Quote Originally Posted by John Koehrer View Post
    Or, the most common is loose set screws in the focusing ring.
    To fix it, set focus to infinity, loosen the screws a bit and set the ring so it lines up. Tighten the screws.
    This is a great advice and might hopefully solve the problem. Those set screws loosening over the decades and slipping is certainly the likeliest explanation, however I do have a cautionary tale.

    I once sorted out (so I thought) a couple of Takumars in this way. They were focussing slightly past infinity on a Spotmatic SP II. Took me an embarrassingly long while to realise that it was in fact the camera body, and not the lenses, that was out of whack

    If possible, before doing anything else it would be useful to check the lens on another camera body. If the lens exhibits the same focussing scale error on another camera, you'll know for definite where the error lies.

  6. #6

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    Mar 2012
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    Quote Originally Posted by oreston View Post
    This is a great advice and might hopefully solve the problem. Those set screws loosening over the decades and slipping is certainly the likeliest explanation, however I do have a cautionary tale.

    I once sorted out (so I thought) a couple of Takumars in this way. They were focussing slightly past infinity on a Spotmatic SP II. Took me an embarrassingly long while to realise that it was in fact the camera body, and not the lenses, that was out of whack

    If possible, before doing anything else it would be useful to check the lens on another camera body. If the lens exhibits the same focussing scale error on another camera, you'll know for definite where the error lies.
    Great advice, I will start with this...

  7. #7

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    May 2008
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    Hello,
    you find several very useful links in the net how to open and repair this lens with many pictures and even movies. The infinity lock is not made by the set screws in the outside focussing ring but there are fixing screws who stop the rotation of the complete lens barrel in the helicoil. If this doesn't work, the lens barrel has been put back into a wrong entrance of the multi-thread helicoil by somebody who did'nt know what he does. At first you have to check the correct infinity focus in the film plane and then you fix the screws slightly loosened before. You get into the lens after removing the front inscription ring in the filter thread with a rubber tool. This is a great lens and worth fixing it.

  8. #8

    Join Date
    Jun 2011
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    Quote Originally Posted by jochen View Post
    Hello,
    you find several very useful links in the net how to open and repair this lens with many pictures and even movies. The infinity lock is not made by the set screws in the outside focussing ring but there are fixing screws who stop the rotation of the complete lens barrel in the helicoil. If this doesn't work, the lens barrel has been put back into a wrong entrance of the multi-thread helicoil by somebody who did'nt know what he does. At first you have to check the correct infinity focus in the film plane and then you fix the screws slightly loosened before. You get into the lens after removing the front inscription ring in the filter thread with a rubber tool. This is a great lens and worth fixing it.
    These screws are actually the ones I had in mind! (Reading back, and as Jochen points out, I realise that the earlier poster was talking about the tiny screws on the outside of the barrel). The front name ring will unscrew anti-clockwise. An improvised tool like an M42 rear lens cap with some duct tape or something similar around the edge is usually all you need to get it turning. Then there are just three screws to remove the part with the filter thread and you're in. The screws that secure the lens tube to the helical can then be slackened off and you can make the necessary adjustments as above.

  9. #9

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    Mar 2012
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    Thanks everybody for advising me. I checked the lens on another camera and it has the same issue, so most likely you were correct with the diagnosis...

  10. #10

    Join Date
    Oct 2013
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    I guess I'm confused.

    a) Will the lens focus to infinity, ie, you can take a picture of something at infinity, and it will be in focus, but the barrel markings show it to not be at infinity?

    Or

    b) When you turn the focus ring to the infinity mark, the actual point of focus is about 10 meters away?

    When I responded, I read the issue as b.

    Also, i found a great 'tool' for removing the beauty ring, and other similarly secured parts on lenses - http://www.homedepot.com/p/Oatey-3-i...3402/100168770
    It has a nice big hole in the middle that's tapered, so nothing touches the actual glass, and it's cheap. It comes in a couple of sizes, can't remember which size I have (2-1/2"?).

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