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Thread: Konica Hexar AF

  1. #11
    df cardwell's Avatar
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    The Mandler Summicron is a copy of the W-Nikkor ?

    :o
    "One of the painful things about our time is that those who feel certainty are stupid,
    and those with any imagination and understanding are filled with doubt and indecision"

    -Bertrand Russell

  2. #12

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    I didn't say that. Summicron f/3.5 lenses are a different story.

    I said that W-Nikkor 3.5cm f/1.8 was the originator of this type of Xenotar-derived semi-wide angle with large aperture (f/2 or less), completed in mid 1950s. Sumicron 35mm f/2 was sold a few years after the W-Nikkor was sold. A version of Summicron (1979) similar to W-Nikkor was sold only after the Nikon patent expired. Hexanon 35mm f/2.0 is a modern example of W-Nikkor type design, sold long after Nikon patent expired, and also after Leitz Summicron of 1979. I think the similarity is overemphasized in popular press and weblogs, because Hexanon was redesigned to fit the dimensional constraints from the camera design.

    But none of these affects the image quality of Hexanon 35mm f/2. Konica had excellent optical engineers who were very good at picking the best design and further optimizing to their design goal. People generally know Konica as the pioneer of all sorts of radical/strange new things, but this was not all they did. (Unfortunately we see many of these examples in compact cameras, especially after they went the wrong direction in their SLR product lines.)

    I should add one very unique point of the Hexanon 35mm f/2 built in to Hexar AF. Spherical aberration of this lens is undercorrected to ensure high contrast image from wide open. Usually, when this approach is taken, there is shift in plane of best focus as the aperture is varied. This is unacceptable for rangefinder cameras and SLR cameras, as focus and aperture must be controlled orthogonally. However, Hexar is an autofocus camera with a built-in computer that calculates the shift in focusing based on the aperture value, and adjusts the focusing scale on the fly. So the optics designer had more freedom in the design approach with Hexar AF (It's described in the Konica technical report linked above.)

  3. #13
    df cardwell's Avatar
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    The 35/1.8 W-Nikkor was designed by Azuma in 1955 ( according to Nikon ) and hit the market in 1956. It is a 7 element lens using a Lanthanum element. Wonderful lens.

    The 35/2 Summicron appeared in 1958, 6 elements. Looking deeper than the largely irrelevent block diagram, it is an evolution of the double-gauss experience of Leitz that dates back to Berek's work in the early '30s.

    The Summicron's 6 element design had 3 iterations, and was replaced in 1980 by Mandler's 7 element design. Mandler's appreciation of the double-gauss design was revolutionary, as had been Azuma's, and his designs are not evolutions of Leitz tradition nor any potential influence from 20 years before.

    The design era from 1950 to 1980 saw the double-gauss design go through astonishing developments. It is poetic, and probably accurate enough, to view Azuma and Mandler as bookends of the period.

    Here are diagrams ( largely irrelevent ) of the 1956 W-Nikkor and the 1978 Summicron:
    Last edited by df cardwell; 07-28-2006 at 10:34 AM. Click to view previous post history.
    "One of the painful things about our time is that those who feel certainty are stupid,
    and those with any imagination and understanding are filled with doubt and indecision"

    -Bertrand Russell

  4. #14

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    I don't really agree that Mandler wasn't aware of and uninfluenced by the Azuma's design, which made the world's first lens of that specification.

    W-Nikkor and Summicron 35/2 of 1979 differed most obviously in the last two elements, where one recognizes the originality of W-Nikkor design. But the additon of the elements after Xenotar-type lens improved coma, spherical aberration and field flatness in both designs.

    W-Nikkor and Hexanon 35/2 of Hexar AF differed in the 2nd and 3rd elements. While the 2nd and 3rd elements are cemented in W-Nikkor, Hexanon separated them to increase the negative power in the front group, which was necessary because they had to increase the distance between the front and rear groups.

    So my point is in response to jimgalli that Hexanon 35/2 is derived from W-Nikkor, to which it is much more similar than Summicron. But all these three lenses share the same line of techniques. People often believe Hexanon 35/2 to be a close copy of 1979 Summicron, where Hexanon is in fact closer to W-Nikkor design and is better viewed as a variation of the W-Nikkor. If anyone argues that Hexanon is a copy of Summicron, then Summicron is a copy of W-Nikkor.

    Again, my view is that the similarity is overemphasized in popular press and online commentary.

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    Hi John

    I've had mine for a few months and love it, it's larger than I'd like, it's about the size of an m6 or so, and the lens is fixed, but the lens is superior, I doubt you can find a lens of this quality for the price of a hexar with lens. The autofocus and metering is also excellent.

    Note that in "M" manual mode, the metering goes to spot, so keep this in mind. A mode is great in that it will always take the picture, and use your preset aperture, even the P mode is great in which it will always attempt to use where you set your aperture, but will not take a photo if it decides shutter speed is too slow or fast. Note the highest shutter speed is 1/250, I haven't run into a problem yet, but can easily foresee this in bright daylight with fast film. You can override the auto-DX.


    Quote Originally Posted by thebanana
    I'm seriously considering buying one of these babies. I'd be interested in hearing from anyone who has experience with them. What should I be looking for when kicking the tires? Cheers,

    John

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    I had one for quite a while - very nice camera. You can usually turn the "stealth" mode back on in most of the later models yourself as well

  7. #17

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    Tell me about my lens

    Interesting thread. I really enjoy using my Konica Auto S2 rangefinder circa 1965 vintage . It has a 45mm Hexanon 1.8 lens with CopaL-sva shutter.

    What can you tell me about the lens design?

    deebel

  8. #18

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    Quote Originally Posted by deebel
    Interesting thread. I really enjoy using my Konica Auto S2 rangefinder circa 1965 vintage . It has a 45mm Hexanon 1.8 lens with CopaL-sva shutter.

    What can you tell me about the lens design?
    I have two of those myself and I love them. But I haven't seen a diagram for these lenses. I took apart lenses and looked at individual surfaces; it's 6e 4g design, with 3e 2g in each side of the shutter. I've heard that the design is similar to Ektar 45/2 or 47/2, but I haven't confirmed this myself.

  9. #19
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    The S2 was an impressive image maker and compares favorably to modern day optics. The amazing little rig to me was the S3. I was recently printing some old negatives that included some S3 on FP4 images and I just can't imagine asking for more from 35mm. The camera had a very clever GN/fill light metering system and though the lens felt a bit loose by virtue of its attachment design, I never felt that it impacted the image. The Hexar, in some ways, is a polished up, complicated method to a similar result. I very much like my little Hexar but because of periods of time elapsing between uses, I'm always just a bit muddled when getting used to it each time. If it was my primary camera, it certainly would feel more intuitive from more consistent usage. Hexanons were the "sleepers" among the makers and I greatly mourn their passing!
    Craig Schroeder

  10. #20

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    Quote Originally Posted by Ryuji
    I haven't seen a diagram for these lenses. I took apart lenses and looked at individual surfaces; it's 6e 4g design, with 3e 2g in each side of the shutter. I've heard that the design is similar to Ektar 45/2 or 47/2, but I haven't confirmed this myself.
    Don't take this as anything more than speculation at this point, but this has been bothering me for some time. I have no diagram or design episodes for Hexanon used in Auto S2. But comparing my sketches to known good (and cheap) designs of 40-50mm f/2 at that time, it became very obvious that most of them are Planar design with minor variations from Rudolph's design. Examples include Rikenon 45mm f/2 (used in Ricoh 35 Delux L, f/2 model, lens made by Showa optics).

    There is one difference between Rudolph's design and modern Planar's of 6e4g construction, such as 45mm f/2 used for Contax G, etc. The difference is in the cemented surfaces. Even among 6e4g constructions, there are variations. (And there are 6e5g type where the front group is uncemented, and more variations with 7 or 8 elements, and then...)

    I tool the lens apart to find Hexanon 45mm f/1.8 in Auto S2 was 6e4g but I didn't uncement the elements to determine the cemented surfaces. We need more information in this area.

    My bet is that the lens is similar to Rikenon 45mm or original Planar.

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