Is there a website showing the cross section of a modern autofocuslens and how the autofocus mechani

Discussion in 'Digital Photography' started by aniramca, May 29, 2009.

  1. aniramca

    aniramca Guest

    Just curious to know how the lens barrel is moving up or down when you
    press the camera's button. It must drain a lot of energy from the
    battery to do this. I recall the old autofocus lens was a monster
    size. Is there a diagram somewhere in the web which shows how this is
    accomplished? Is there some kind of a spiral screw along the outer
    skin of the lens barrel? I also assume that the bigger the lens, the
    more energy needed to move the lens during autofocusing.
    Thanks for the info.
     
    aniramca, May 29, 2009
    #1
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  2. aniramca

    Don Stauffer Guest


    I have seen such diagrams, but do not have a reference to any right now.
    Consider too that it is not unique to autofocus. Remember that when
    you do manual focus you only move one ring, you do not have to move
    individual elements. Yes, frequently the mechanism employs a coarse
    pitch helical groove or "thread". Consider that a small motor could be
    geared down to move the focusing ring.

    Most lenses are pretty well made these days with high precision and so
    very little friction. As a result they do not take a LOT of energy, but
    they certainly do take some. As a result, some camera manuals do say
    that using manual focus, if available, will lead to longer battery life.
     
    Don Stauffer, May 30, 2009
    #2
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  3. aniramca

    me Guest

    On Fri, 29 May 2009 14:18:58 -0700 (PDT), in rec.photo.digital
    Some discussion of the Nikon SWM lens design may be found here.
    http://imaging.nikon.com/products/imaging/technology/scene/03/index.htm
     
    me, May 30, 2009
    #3
  4. aniramca

    aniramca Guest

    I finally found a website (all the way from Malaysia) which shows a 3D
    slice of a Nikkor autofocus lens
    http://www.mir.com.my/rb/photography/companies/nikon/nikkoresources/AFNikkor/index.htm

    I wonder if there are other websites that show this in more great
    details.
    According to the 3D section, it looks to me that the motor gear is
    located directly under the ring grip where you twist the lens when you
    want to change the zoom distance manually. It is neat! I am curious
    about this, as I seem to notice that my cheap Nikkor autofocus
    70-300mm lens feels rather flimsy on the plastic outer barrel and
    wonder where the motor mechanism is located and how it works. Although
    it is relatively cheap, I could not afford to send my lens to a
    machine saw and cut it into half in lengthwise to find out where the
    mechanism is :)
    I would love to see more about this autofocus lens info, if someone
    has more info or amke reference to websites.
     
    aniramca, May 31, 2009
    #4
  5. aniramca

    Bob Larter Guest

    Somebody recently posted the complete service & parts manual that
    covered several Canon prime lenses, which had detailed diagrams &
    explanations for all this stuff. Maybe someone else here still has the URL.
     
    Bob Larter, Jun 1, 2009
    #5
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