Nikon's new 105mm with selective defocus

Discussion in 'Nikon' started by RichA, Jul 24, 2007.

  1. RichA

    RichA Guest

    Does anyone know how this works? It can actually electronically
    increase the blur in the out of focus areas to improve backgrounds.
     
    RichA, Jul 24, 2007
    #1
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  2. RichA

    C J Campbell Guest

    Got a link for this lens? The only lens I know of that does anything
    like that is a 105mm portrait lens, the 105mm f/2D AF DC-Nikkor.
     
    C J Campbell, Jul 24, 2007
    #2
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  3. RichA

    Guest Guest

    that's the lens. it does it by increasing the aberrations, not with any
    electronic blur.
     
    Guest, Jul 24, 2007
    #3
  4. RichA

    RichA Guest

    Yes, but supposedly, the in-focus subject isn't blurred. The only way
    this could be done is by the
    camera, likely post-sensor.
     
    RichA, Jul 24, 2007
    #4
  5. RichA

    frederick Guest

    No.
    Without even having to consider the details, just note that such lenses
    were designed for film cameras, not digital.
    That's a better starting point than an incorrect assumption.
     
    frederick, Jul 24, 2007
    #5
  6. RichA

    Paul Furman Guest

    There is a 135mm DC Defocus Control and another one I think. And yes, it
    adjusts the aberrations so you can choose to have the smoothestblur
    either in the foreground or background, and it's very subtle. I've not
    seen anyone actually demonstrate the difference. It's supposed to be a
    really nice lens though.

    http://www.google.com/search?q=135mm+f/2+DC
     
    Paul Furman, Jul 24, 2007
    #6
  7. RichA

    Jeremy Nixon Guest

    Uh, no. First of all, the lens isn't at all new, it's been out since 1993.

    What the defocus control does is control the spherical aberration correction
    in the lens. The character of the out-of-focus rendition of a lens depends
    greatly on this, so changing it changes the "look" of the defocused part of
    the image. If you dial in over-correction or under-correction, it becomes
    a soft-focus lens, so you can have that without having to buy a lens that
    *only* does that.

    Since the correction in a lens can either lend smoothness to the background
    out-of-focus areas, or the foreground out-of-focus areas, but not both, this
    lens also lets you choose which of the two you want to be smoother, depending
    on what you're shooting. If your main out-of-focus area is in the foreground,
    then you adjust it to render that smoothly, while a "normal" lens would
    almost certainly be corrected in the other direction.

    I do have the lens, and it is quite nice.
     
    Jeremy Nixon, Jul 24, 2007
    #7
  8. RichA

    Guest Guest

    if that were true, why would there need to be a special lens? or just
    do it in photoshop.

    the lens lets you control the aberrations. it is unquestionably not
    electronic.
     
    Guest, Jul 24, 2007
    #8
  9. The 135mm f/2.0 DC is a nice lens, but on a 1.5x crop dSLR I find
    myself using it as a fast medium telephoto. In that role, the
    feature isn't particularly useful. The extra complexity may also
    cause some calibration issues -- more than one person has reported
    that some adjustment of the defocus ring is required to get the
    sharpest image.

    The best page I know of describing and demonstrating the effect is at:
    http://www.stacken.kth.se/~maxz/defocuscontrol/
     
    Michael Benveniste, Jul 24, 2007
    #9
  10. RichA

    Paul Furman Guest

    Ah, thanks for that!
     
    Paul Furman, Jul 24, 2007
    #10
  11. RichA

    george Guest

    Take a look at the current issue of Popular Photography...they test the
    135mm DC and show the difference. It is VERY subtle and mostly mutes the
    specular highlights in the blurred areas. (Keeps the eye looking at the
    subject rather than unusually bright highlights out of the area of the
    subject.) They also reported a very slight lowering of contrast.
     
    george, Jul 24, 2007
    #11
  12. RichA

    C J Campbell Guest

    That is why I asked for a link to this lens he was talking about -- the
    only one I knew about worked optically.
     
    C J Campbell, Jul 25, 2007
    #12
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