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Thread: Corrections on a copy lens: -3 ,-8 ,+4, +4, +12

  1. #1
    Embdude's Avatar
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    Corrections on a copy lens: -3 ,-8 ,+4, +4, +12

    Can someone please explain the significance of the correction number on a copier lens?

    As an example of what I am asking about there is an auction on ebay with a similar but not quite identical lens set...

    "5 Bausch & Lomb (B&L) copy lens set with mount. They are all the same lens: 209mm F4.5 BUT they have different visual corrections. Corrections on the lens: -3 ,-8 ,+4, +4, +12"
    https://www.ebay.com/itm/26500101100...rEeqDADhx1iSqY

    Are these correction numbers common to copy lenses and what do they mean?

    Thanks
    Last edited by Embdude; 14-Feb-2022 at 16:24. Reason: changed from copy to copier lens

  2. #2

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    Re: Corrections on a copy lens: -3 ,-8 ,+4, +4, +12

    Donít you mean a copier lens?

  3. #3
    Embdude's Avatar
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    Re: Corrections on a copy lens: -3 ,-8 ,+4, +4, +12

    Quote Originally Posted by Bob Salomon View Post
    Don’t you mean a copier lens?
    Probably. I do not know the proper terminology I'm afraid, but I'm willing to learn.
    Copy camera, Process lens, Copier lens, Projection lens, Enlarging lens, are these describing specific designs or just describing the intended use, or both?

  4. #4

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    Re: Corrections on a copy lens: -3 ,-8 ,+4, +4, +12

    Quote Originally Posted by Embdude View Post
    Probably. I do not know the proper terminology I'm afraid, but I'm willing to learn.
    Copy camera, Process lens, Copier lens, Projection lens, Enlarging lens, are these describing specific designs or just describing the intended use, or both?
    Specific lenses for specific uses.

  5. #5
    Embdude's Avatar
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    Re: Corrections on a copy lens: -3 ,-8 ,+4, +4, +12

    Thanks Bob. So the +/- corrections are these something specific to copier lenses or are would they also be used on process or other types of lenses?

  6. #6

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    Re: Corrections on a copy lens: -3 ,-8 ,+4, +4, +12

    Quote Originally Posted by Embdude View Post
    Thanks Bob. So the +/- corrections are these something specific to copier lenses or are would they also be used on process or other types of lenses?
    Probably a setting for technicians working on the copier.

  7. #7

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    Re: Corrections on a copy lens: -3 ,-8 ,+4, +4, +12

    One more possibility -- I can't see the picture, EBAY can't find it -- Fujinon EFC lenses for photo processing machines (developing & printing) have similar number -- without the + / - , from 1 to 15, for example. They are not aperture settings. They are distance settings, perhaps for particular machines or film formats, etc.
    Last edited by xkaes; 14-Feb-2022 at 18:35.

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