Lens Disassembly?

Discussion in 'Medium Format Cameras and Accessories' started by ParkerSmithPhoto, Jan 9, 2012.

  1. ParkerSmithPhoto

    ParkerSmithPhoto Subscriber

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    I have an old 80mm Bronica SQ lens and I was thinking about removing the rear lens element (only) to emulate the look of my old Diana camera.

    If I do remove the rear element, will the lens still focus on the film plane, if even somewhat marginally? Or, is this a non starter?
     
  2. DWThomas

    DWThomas Subscriber

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    I believe all the Bronica lenses below perhaps 150 mm or so are "retrofocal" designs that play tricks because the lens mount to film plane distance is about 90 mm. As such, the rear element could possibly be a negative diopter which won't focus at all as a single element. (But I haven't taken any of mine apart! :D)

    The odds are that any individual elements will have a considerably longer focal length than the combined package.

    My 1.4 (after tax) cents,

    DaveT
     
  3. bdial

    bdial Subscriber

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    Depends on the design of the lens, for example, the older "convertable" symars can be used with only the front or the rear group, but the focal length is around double that of the complete lens. So, if this were true of your Bronica lens, (and it likely is not) you'd need a fairly long extension tube to get the lens to a place it could be focused.

    If you're just looking to make things soft, you could possibly unscrew the element a few turns, some of the soft focus lenses work in exactly this way. If you're looking to get vignetting, a deep lenshood might work well.