Mamiya RB67 180 C Lens Dust Inside

Discussion in 'Medium Format Cameras and Accessories' started by Marco S., Oct 19, 2006.

  1. Marco S.

    Marco S. Member

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    I have a 180 C lens for my RB67 Pro S that has some dust or flecks of something behind the front element. If I gently tap the lens most of it settles.

    Does anyone know if there is a way to clean them out or if it may affect the picture quality?

    Marco
     
  2. Dave Parker

    Dave Parker Inactive

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    Unless it is heavy dust and a lot of it, I would not worry about it, at worst you might, just maybe get a small change in contrast, but many of my lenses have dust in them, due to the enviorments I shoot in and the black flocking inside them comming loose over the years, I have never noticed any problems in my pictures, so I would really not worry about it, of course this is only my opinion, others may have a different take on things. I have some lenses that have scratches, pretty deep ones at that on the front element and they don't affect my pictures either.

    Dave
     
  3. Marco S.

    Marco S. Member

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    That's very reassuring, thank you. I need to learn not to obsess over these things too much and take more pictures.

    Marco
     
  4. Michael W

    Michael W Member

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    I've been told that it's fairly common for medium format lenses with leaf shutters (shutter in the lens) to have dust. It can be tiny bits of metal that come off as the blades slide over each other in opening & closing. A good technician can open it up & clean out but mostly it doesn't affect the picture, so why bother.
     
  5. Pragmatist

    Pragmatist Member

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    It does not take a technician to clean out this lens. The large front element assembly unscrews quite readily from the shutter body. Once the forward elements have been unscrewed, it is a simple matter to open the aperature and shutter, blowing out any dust that has accumulated. I have done this to my 180, 90, and 65 C lenses. Just make sure that you do not cross thread when putting the lens back together, and tighten firmly. Otherwise, the lens assembly will twist when you put on a filter or shade coupler...
     
  6. Marco S.

    Marco S. Member

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    The flecks are inside the main element, not between the lens and shutter. Just behind the front element glass, as if static electricity is holding it there. But I do understand what you mean. Getting apart the large front element once removed from the lens body is what I can't seem to figure out. Best just leave it be, I suppose.

    Marco
     
  7. Elox

    Elox Member

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  8. Pragmatist

    Pragmatist Member

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    It takes a spanner to unscrew the bezel (the part with the printing) from inside the lens. Then, the spanner is used to remove a jam nut that holds the front element assembly in. An alternate method is to unscrew the main element assembly from the shutter body, and remove the jam nut that holds the rear elements in place. Compressed air can then be directed to the back of the front element array.

    But as Elox posts, chances are it is nothing that will impinge on the general quality of your image. I keep all of my lenses free of stuff like this just on GP...
     
  9. epatsellis

    epatsellis Member

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    You mean that they're not supposed to have dust inside them???? next you'll tell me that the front elements shouldnt' have scratches in them I bet.

    erie
     
  10. eddie gunks

    eddie gunks Member

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    har har! good one erie.

    i have a sekor 90mm that has bad dust. it never shows up.....ever. on my 250mm i accidently unscrewed the from element while trying to remove my polarizer. it is pretty easy to do.

    don't fix it is it aint broke.

    eddie

     
  11. epatsellis

    epatsellis Member

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    That's no big deal, my 150 SF does that all the time, of course, I"m usually changing one of the diffusion discs when I do that, though. I've had a few that needed disassembly and cleaning, C versions mostly, due to internal fogging (prob evaporating lube vapors, think hot trunk in summer.)

    erie
     
  12. Pragmatist

    Pragmatist Member

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    You may be right about the lubrication materials. My 180 and 65 came from completely different sources and both had a mild fogging on the internal elements that required cleaning. The 90 merely had dust between the cells making up the front assembly, and in the shutter body. Being one that has difficulty putting on a postage stamp crooked, I had to clean them out...
     
  13. paul ron

    paul ron Member

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    The 180mm lens doesn't have a rear cell so cleaning the back of the front lens cell is easy to do without removing the lens. But if you say the dust particles are between the front cell's glass, then perhaps taking the front element off with a spanner is indeed the only solution. I don't understand how this dust could have gotten in since the cell is usually sealed quite well. I wounder if the e-bay sales person tampered with the lens prior to selling it?

    Have it checked, most repairmen won't charge you for a peek. I'll take a look at it, just pay round trip postage. If I can do the CLA to fix the dust problem, I get $50. If I can't get to the dust, I'll send it back and not charge you anything for the look.

    E-mail me at automax1@juno.com
    Paul, NYC