Summicron-C 40mm

Discussion in 'Leica and Rangefinders' started by john_galloway, Oct 3, 2000.

  1. Does anyone know where on the web I could find a schematic of the Summicron/Rokkor 40mm? Is it like the Summicron 50 or 35?
     
  2. Here is a website that has a lot of info on the CL / CLE, including
    the lenses. The author makes good comments about the relative
    comparison between the 40mm lenses and "true" Leica lenses...
    basically, they are very well matched... comments about 30 X 40 inch
    prints made with the 40. I think that you are requesting a cut-a-way
    view, showing the elements... sorry, but I could not find one on the
    net with all of my bookmarked leica sites. Hopefully, this site will
    at least give you confidence that the lenses are great.

    <p>

    http://www.cameraquest.com/leicacl.htm
     
  3. Found a couple of other sites... still no cut-a-way view, but one
    site has Chart with elements and groups.

    <p>


    Elements / groups:

    <p>

    http://www.cosmonet.org/camera/leiccl_e.htm

    <p>


    Lens Compatibility:

    <p>

    http://www.multimania.com/cesarigd/photoe2cleo.htm
     
  4. A point to note here is that schematics published over the years, in
    several books, such as The Leica Compendium, or the Leica Manual, or
    Photgraphic Optics by Cox, show that the 50mm Summicron doesn't even
    resemble itself too closely in its various versions. For this reason
    it might be difficult to divine much about the 40mm, or how it
    compares to other Summicrons. I should imagine it probably is a
    gaussian design, with a pair of cemented groups, each having a deeply
    concave surface facing each other from opposite sides of the
    diaphragm; possibly a thin lens airspaced and interposed between one
    or both of those concave surfaces, and the diaphragm; and single
    element positive components for the front and rear elements. This is
    the basic setup of the 35mm Summicron of the time period. But, then
    again, the 90mm Summicron doesn't adhere to this type of formula, and
    this too makes me question how much we can figure out by examining
    the schematic. Why not ask some users to comment on the performance
    of the 40? I think it's supposed to be good, but I've not used one.

    <p>

    Regards,
     
  5. I looked at the website Al Smith cited (I should have done this in
    the first place). The lens has 6 elements in 4 groups. If you have
    access to the Leica M Compendium, take a look at the 35mm Summicron
    on page 51. Now, take away the thin lens just to the right of the
    diaphragm, and the remaining components, I feel pretty sure, would
    bear a close resemblence to the 40mm Summicron.

    <p>

    That's the best I can do. Hope it helps.
     
  6. Thanks for that good site.
     

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