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  1. #11

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    What an education!

  2. #12
    Ole
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    A little more?

    Back in 1866, Steinheil in Germany and Dallmeyer in England patented virtually identical lenses at practically the same time. Steinheil called his "Aplanat", and Dallmeyer called his "Rapid Rectilinear".

    Both of those names make some kind of sense, but to understand why they make sense we have to go back to what was available before then:

    The earliest lenses were simple meniscii (plural of "meniscus"), which had a fairly wide field but lots of distortion, poor speed and lots of field curvature. Then along came Maximilian Petzval and his rapid portrait lens which was fast enough to take portraits in a single sitting without breaking for tea...

    But that didn't help the landscape and architecture photographers much, since Petzval's lens only had about 10 degrees of sharp coverage (look at Jim Galli's wonderful pictures, which show very clearly what happens outside the sharp center).

    So the race was still on, to make a lens with a minimum of distortion and a maximum of speed. Putting two equal meniscii together, one on each side of a central stop, solved the distortion problem. But to get acceptable coverage you were still limited to about f:22...
    Cementing two elements of different refractive index together allowed construction of achromatic lenses, which eliminated the bothersome "focus shift": The human eye tends to see the sharpness as best when yellow light is in focus, but photographic materials were only sensitive to UV and blue light. If blue and yellow focus at different planes you need to correct for the difference between so called "Chemical focus" and "Optical focus".

    Achromatic landscape lenses had good sharpness over a reasonably wide field, but were no faster than f:10 and really needed to be shot at f:32 to be any good. And the distortion was still there.

    So someone put two of these "achromats" together like had been done with the Periskop, and the result was a reasonably fast distortionfree lens. This idea was so simple that noone knows who did it first, and it was sold under a staggering number of different names for some years. They were still only f:10 or so, but at least they were usable on calm days.

    What Dallmeyer and Steinheil did was to reverse the order of the elements in each cell, putting the high-index negative element on the outside and a lower-index positive element on the inside. This gave a lens that had (a) a reasonably flat field, (b) no distortion, (c) no focus shift, and (d) all of this at a wider aperture than the old "symmetricals".

    So Dallmeyer named his lens "Rapid Rectilinear" since it was faster than earlier rectilinear lenses.

    and Steinheil used "Aplanat" for the flatter image field than earlier lenses with similar coverage (like his own Gruppen-Antiplanet)!
    -- Ole Tjugen, Luddite Elitist
    Norway

  3. #13
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    For some reason, to me lens names and the names of drugs sound similar. I can easily imagine putting a 100mm Lipitor on one of my cameras.

  4. #14

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    Chazzy, I was thinking that very thought when I posted this thread! You could have the 240mm f/1.4 Dexedrine, 1200mm f/16 Sildenafil (covers 20x24 with movements), 8mm f/5.6 Haloperidol (a low-distortion, full-frame fisheye ) and the 450mm f/8 Venlafaxine (a soft-focus portrait lens that makes everything look better).

    I feel a new joke thread coming on...

    - Justin

  5. #15
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    Quote Originally Posted by glennfromwy View Post
    I think they just eat spicy food before they go to bed. Gives 'em bad dreams and such.
    Its cheese before you sleep that gives you 'cheese-dreams' Never had spicyfooddreams though

  6. #16
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    Quote Originally Posted by Chazzy View Post
    For some reason, to me lens names and the names of drugs sound similar. I can easily imagine putting a 100mm Lipitor on one of my cameras.
    And maybe a Viagron for a big, long telephoto??
    Eddy McDonald
    www.fotoartes.com
    Eschew defenestration!

  7. #17
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    Quote Originally Posted by eddym View Post
    And maybe a Viagron for a big, long telephoto??
    Or a zoom.

  8. #18
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    Quote Originally Posted by eddym View Post
    OK, so how do we explain the Lensbaby?
    Maybe the inventor was called 'Len', hence 'Lensbaby':rolleyes:
    Norman is an island.Time and tide wait for Norman.

  9. #19
    AgX
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    Well, I looked through hundreds of lens names. You can divide them into names hinting via Greek or Latin at their characteristics, referring to the manufacturer or being pure fantasy-names.


    My all-time-favourite could have become
    the “SCHNELLARBEITER” lens.

    I don’t think the name is related to the aperture.

    (However there is quite a chance that its name relates to the lens designer E. Arbeit.)

  10. #20
    Ole
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    One of the doubtful ones is the Voigtländer W.Z.

    It could have been an abbreviation for "Weichzeichner" or "soft renderer", except that then there wouldn't be full stops after both letters. So the most likely explanation is that it got its name from the person who first asked for it, one Walter Zilly. Silly enough, just as silly as a deliberately soft enlarger lens?
    -- Ole Tjugen, Luddite Elitist
    Norway

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