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Thread: Kern Switar 25mm f1.4 focusing problem

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    Kern Switar 25mm f1.4 focusing problem

    Hello, I'm in need of someone that's familiar with the focusing mechanism on a Kern Switar 25mm 1.4.

    I have it mounted using a RJFinance c to m43rds adapter on my G1. When I turn the focus ring, nothing happens. It turns smoothly but no change in focus. It rotates and stops just short of infinity mark at 50m.

    In fiddling with it, there are three little set screws around the perimeter of the focus ring. Should those screws be lose? If I tighten them the focus ring doesn't move.

    Does anyone have any ideas as to what the problem could be?

    Just as an aside, in order to focus I have to unscrew the lens a little less than a quarter turn to focus at about 30-40 meters and about a half turn to focus 3 or so meters using f/5.6. Test pictures below.

    Appreciate any insight...

    3-4 meters - focus on little figurine.... unscrew half turn.



    30-40 meters - focus on horse head far wall.... unscrew < quarter turn.


    Thank you and cheers,
    Don

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    Re: Kern Switar 25mm f1.4 focusing problem

    Quote Originally Posted by slosync View Post
    Hello, I'm in need of someone that's familiar with the focusing mechanism on a Kern Switar 25mm 1.4.

    I have it mounted using a RJFinance c to m43rds adapter on my G1. When I turn the focus ring, nothing happens. It turns smoothly but no change in focus. It rotates and stops just short of infinity mark at 50m.

    In fiddling with it, there are three little set screws around the perimeter of the focus ring. Should those screws be lose? If I tighten them the focus ring doesn't move.

    Does anyone have any ideas as to what the problem could be?

    Thank you and cheers,
    Don
    Many thanks to lcubed who sent me a PM and helped answer the problem. The 3 set screws were supposed to be tightened down and after that I was able to rock the focus ring back and forth enough to loosen it and it now functions quite reasonably. It most likely needs to be cleaned and lubricated to get it in A+ shape.

    It's a great forum where help is so freely offered.

    Relieved and thank you again lcubed,
    Don

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    Re: Kern Switar 25mm f1.4 focusing problem

    Hi I have the same problem with a Switar 10mm f1.6 H16RX lens. The focus ring turns smoothly but doesn't focus the lens.

    Could you please contact me with instructions on how to resolve this, I am a student and am afraid to damage the lens as it cost me a lot of money.

    Thanks in advance

    Thomas

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    Member slosync's Avatar
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    Re: Kern Switar 25mm f1.4 focusing problem

    Quote Originally Posted by thmreev View Post
    Hi I have the same problem with a Switar 10mm f1.6 H16RX lens. The focus ring turns smoothly but doesn't focus the lens.

    Could you please contact me with instructions on how to resolve this, I am a student and am afraid to damage the lens as it cost me a lot of money.

    Thanks in advance

    Thomas
    Hi Thomas,

    As I recall in my case the set screws on the focus ring needed to be tightened down. However when I did I could not turn the focus ring because it was "frozen" due to a lack of lubrication (actually the lubrication had become dried....). To loosen the focus ring after tightening the set screws I gripped the focus ring and began to rock it back and forth, back and forth.... and ever so slowly, millimeter by millimeter, it began to loosen to a point where I could focus the lens. It never really loosened up to where it was easy to turn, but I could turn it to focus.

    Net net: In my case the focus ring set screws were loose and needed to be tightened. Your aren't actually turning the focus mechanism in the lens unless the three set screws are tightened. (As stated above, it was then I discovered the focusing mechanism was "gummed up" and needed to be forcibly worked back and forth to "free" it up. This may not be the prudent approach to correct the problem however, having it repaired is probably a better route to take.

    Good luck,
    Don (a.k.a. slosync)

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    Re: Kern Switar 25mm f1.4 focusing problem

    Fwiw, I eventually sent my 26mm f1.1 to dieter @ procam (bolexusa) to get mine recollimated for use on m43. The R&R included cleaning and lubrication.

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