design of fujinon 55mm f/2.2 lens

Discussion in 'Fuji' started by sreenath, Aug 20, 2007.

  1. sreenath

    sreenath Guest

    Hi All,

    I am curious to know about the design of fujinon 55mm f/2.2 lens. It
    is listed as 4 element in 4 groups.
    So, it does not make it a Tessar type lens, tessars usually being no
    faster than 2.8.

    It is not also a double Guass design.

    Fuji has another 55mm lens which is of traditional design, 55mm f/1.8.

    Could anyone provide more information about this lens? Is it expected
    to perform as well as a 6 element lens, and did any other manufacturer
    produce similar lenses?

    thanks for any information,
    Sreenath
     
    sreenath, Aug 20, 2007
    #1
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  2. I can't really help, but I did once own a Fujinon 55mm 1.6 (on a
    Fujica ST605, then an AZ-1). Very fine lens although a little prone
    to flare - I recall it had an unusually curved front element. Fuji
    seem to do their own thing quite frequently...
     
    mark.thomas.7, Aug 20, 2007
    #2
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  3. sreenath

    Jim Guest

    Sorry to say, the Tessar design consisted of 4 elements in 3 groups. The
    front two were separate, and the back two were cemented.
    Once upon a time, the max speed (with very good sharpness) of the Tessar
    design was considered to be f3.5. Some companies have
    sold f2.8 Tessars, but these were not the best around. Again, once upon a
    time, the conventional wisdom was the 5 elements provided
    the required number of degrees of freedom for good performance at f2.8.

    I suppose I should mention the Zeiss Triotor f3.5 lens (I have an old
    Rolleicord with one), but these definitely were not as sharp as
    the Tessars. Triotars are cheaper though.

    Perhaps someone wiho owns one of the subject lenses can comment about its
    performance.
    I would be surprised if it does; however, computer aided design of lenses in
    conjunction with aspheric lenses can work wonders.
    Jim
     
    Jim, Aug 20, 2007
    #3
  4. It is probably a symmetric [or close to] lens with 4 meniscus elements
    arraigned around a central stop.

    Sometimes called a '4-element Gauss' [and closer to what Gauss originally
    proposed than the 6-elements that go by that name].

    The design shows up in the Petzval portrait lens, some slide projector
    lenses and in process lenses.

    Basic principle is used in wide-angle view camera lenses like the
    wide-field Ektars.

    In this application it would be as a budget lens with a bit better
    aperture specification than a Tessar. Should be very low distortion.
     
    Nicholas O. Lindan, Aug 20, 2007
    #4
  5. sreenath

    Jim Guest

    To add: Zeiss manufactured a very wide angle lens for the Leica which was
    designed as Nicholas described. Examples of this lens are quite scarce and
    very expensive.
    It is also said to be very sharp and remarkably free from distortions.

    Nikon also used such a symmetrical design for the 25mm f4 lens for use on
    their rangefinder cameras. These lenses are also very scarce and expensive.
    The lens was introduced
    in 1954. Nikon did not remount this lens for the SLR cameras. It was
    supposed to have been quite sharp and lacking in distortions.

    However, it does not necessarily follow that the Fujinon lens will possess
    the traits of these two predecessors.
    Jim
     
    Jim, Aug 20, 2007
    #5
  6. No. The Petzval lens is nonsymmetric in the extreme. It has two
    widely spaced positive two element groups, each of which is
    semi-achromatic.


    Doug McDonald
     
    Doug McDonald, Aug 20, 2007
    #6
  7. You're right ... one group is cemented(?)
     
    Nicholas O. Lindan, Aug 20, 2007
    #7
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