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  1. #1
    ic-racer's Avatar
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    Yashica 55mm f4 ML Macro Repair

    I got a cosmetically nice 55 f4 macro through the mail, but, as usual, there are issues.

    1) Foggy lens elements
    2) Aperture blades covered with oil
    3) Aperture won't close down all the way

    Since it is in very nice cosmetic condition I thought it was worthwhile to salvage it.


  2. #2
    ic-racer's Avatar
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    This well corrected lens has only 4 elements, so cleaning should be easy. The front two unscrew easily and the rear two unscrew easily.
    Though, the rear two elements look like they are permanently sealed together with a rim of metal squeezed over on of the elements. I did not see a way to get them apart. Thats OK because the inner element surfaces were pretty clean. In terms of the front elements, the front surface was the worst. It had the awful oily residue on it and it was a little trouble to get it all off. In the end the glass cleaned up pretty well and underneath the haze there were no scratches or imperfections in the coating.


  3. #3
    ic-racer's Avatar
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    Oil on the aperture blades.
    With all the glass elements removed from the barrel, I was able to flush the aperture mechanism. In this case acetone was used. but be careful. If you get acetone on the outside of the barrel it can take off the numbers. Also, acetone can remove black paint that may be used internally to prevent flare.

    Without taking the entire mechanism out and soaking it, it can be difficult to get the blades clean. New oil keeps seeping out from the perimeter onto the blades. With some persistence I got the blades all clean without having to take the lens helicoid apart to get the aperture mechanism out.

    Bad news is that the aperture still would stick and not close down all the way.

  4. #4
    ic-racer's Avatar
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    Closer inspection of the rear of the lens mount revealed a ball-bearing mechanism for the aperture actuation lever. There was a locking ring over the ball bearings and the ring was too tight, causing the ball-bearings to bind.
    Even closer inspection showed that there had originally been a drop of glue or paint to keep the ring from tightening.

    I loosened the ring to the original position and applied a new drop of paint to hold it in place. The aperture then worked perfectly.


  5. #5

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    Wow, that lens is in great condition. Definitely worth a repair. I'm going to be going through this same journey with a 100mm FD Canon macro, which has some fungus on the inside of the rear element. Hopefully things go as smoothly

  6. #6
    ic-racer's Avatar
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    To avoid frustration, I sometimes bid on items that I know will need work. The 55mm Macro was billed as excellent condition so I almost sent it back.

    Here is an example of the exact opposite: PICTURE LOOKS BAD but LENS IS GOOD
    Another purchase (NOT THE LENS FROM THE ORIGINAL POST), shown below, was anticipated to be a 'project' lens to clean up. It was $20 and I could not tell exactly what it was other than it came up with a search for 'Yashica'.
    It turns out that lens was in mint condition with the original stickers on it! So sometimes you loose and sometimes you win.
    This is the image from the ad:
    Last edited by ic-racer; 10-21-2011 at 02:14 PM. Click to view previous post history.

  7. #7
    ic-racer's Avatar
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    What a good surprise to find that the lens in that blurry picture was essentially brand new with original "Yashica" branded caps!

  8. #8
    ic-racer's Avatar
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    That 28mm lens, by the way, is a desirable third generation 28mm f2.8 7 element lens. This is a re-design of the earlier ML 28mm lens with a lens formula the more closely matches that of the Zeiss 28mm f2.8.
    Early Model Yashica 28 f2.8 ML Lens:

    Late Model Yashica 28 f2.8 ML Lens:

    Zeiss Lens:

  9. #9
    ic-racer's Avatar
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    Quote Originally Posted by ic-racer View Post
    sometimes you loose and sometimes you win.
    And sometimes you can't spell...

  10. #10

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    What is recommended to clean the glass of haze? I have a low-value hazy lens that I would like to clean but am ignorant on the correct fluid.

    Thanks
    - Bill Lynch

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