Fixing scratches on a focusing screen

Discussion in 'Medium Format Cameras and Accessories' started by ParkerSmithPhoto, Nov 4, 2012.

  1. ParkerSmithPhoto

    ParkerSmithPhoto Subscriber

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    Is there any way to freshen up a scratched focusing screen? Both my Bronicas have a variety of scratches which are not terrible, but kind of irritating.

    Thanks!
     
  2. jochen

    jochen Member

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    Hello,
    if the scratches are on the glossy upper side, maybe with a special polishing paste for transparent plastic. If they are on the fresnel side: no chance!
     
  3. 2bits

    2bits Member

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    Hi Jochen,
    I have used "Fitz" on plastic display cases with great success. A lot of plastic modelers use it to buff out plastic windshields. It is a liquid buffing compound, comes in a squeeze tube. Look up Fitz in modeling magazines and websites. I have never tried it on a focusing screen. It's very fine stuff though. Another remedy is old fashion toothpaste, it's also a mild abrasive. I'd follow the advise above on where to use it.
    Good luck,
    2bits
     
  4. Newt_on_Swings

    Newt_on_Swings Member

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    Plastic screens can be resurfaced with plastic polish, again like jochen says only on the transparent side. If its a scratch on the other side the only solution is a replacement. You can surely shoot with it and it wont affect the image, after awhile you wont really notice it, as your brain reconfigures (well mine does atleast).
     
  5. ic-racer

    ic-racer Member

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    Buy a new one.
     
  6. PentaxBronica

    PentaxBronica Member

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    Not always possible. I don't think you can still get brand new screens for the Bronica system, and most used ones seem to have at least a few marks.

    You might want to try the plastic polish or toothpaste on one of the less obtrusive scratches first (say if you have one at the top of the viewfinder), that way if it doesn't help matters you won't make the screen unusable. If it works perfectly then you can attack the rest.
     
  7. lxdude

    lxdude Member

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    True, except the glossy side is the lower side-the fresnel side is the upper side.
     
  8. PentaxBronica

    PentaxBronica Member

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    Eh?

    My ETR and ETRSi have the ground glass on the underside, it must be right as focus is spot on. Always assumed that Bronica did this so that the more robust smooth side was revealed when you changed viewfinders.
     
  9. lxdude

    lxdude Member

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    DOH! I misspoke. The glossy upper side IS the fresnel side. Drag a fingernail or the edge of a piece of paper across it lightly, and you will hear the sound made by the ridges. Or look with a loupe.
     
  10. ic-racer

    ic-racer Member

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    18 different new Bronica screens show up on a B&H site search.