Idea for new focus system....

Discussion in 'Digital Photography' started by MattSepeta, May 30, 2011.

  1. MattSepeta macrumors 65816

    MattSepeta

    Joined:
    Jul 9, 2009
    Location:
    375th St. Y
    #1
    I was thinking about how annoying it is when you are shooting wide open at a very low f-stop,m f/1.4 or f/2, and when you employ the focus-recompose method you will often end up with the eyes, or whatever your desired focus point is being off a bit.

    I came up with an idea of sorts on how a camera could combat this without the pain of selecting a focus point, which I really do not like doing-

    Let's say you are using center point one shot AF. You focus the center point on the eyes, and naturally recompose to a more pleasing composition while your shutter is half pressed. What if the camera would somehow detect that area, and assuming said desired area of focus falls under another focus point once desired composition is obtained, the camera automatically senses this and reconfirms the desired focus using the new, non-manually-selected focus point on the original area of desired focus? I imagine it would do this by employing a very small "snapshot" of the area under the desired focus when you half-depress the shutter, then on-the-fly sensing if this "snapshot" falls under any of the outer focus points while recomposing, where it will finally verify and correct the focus if it does fall under a new focus point.

    It's kind of hard to explain, but I imagine with how "smart" AF is getting (Not counting canon's "5" series of course :p), this is not unrealistic...

    Any thoughts on this? Is it possible? More importantly, is is plausible?
     
  2. compuwar macrumors 601

    compuwar

    Joined:
    Oct 5, 2006
    Location:
    Northern/Central VA
    #2
    This is basically how focus tracking works.

    Paul
     
  3. mackmgg macrumors 65816

    mackmgg

    Joined:
    Nov 2, 2007
    #3
    When shooting in Live View, some cameras already offer something like this as compuwar said. The normal phase-detect autofocus wouldn't be able to do this though, because there is nothing being processed
     
  4. jabbott macrumors 6502

    Joined:
    Nov 23, 2009
    #4
    I'm still waiting for light field digital cameras to come out... it would allow you to choose focus after taking the shot:
    http://graphics.stanford.edu/papers/lfcamera/

    It also provides f/22-like sharpness with an f/4 aperture (not counting diffraction limitations). The tradeoff is lower resolution... but I would often be willing to give up resolution for being able to refocus during post-processing.
     
  5. VirtualRain macrumors 603

    VirtualRain

    Joined:
    Aug 1, 2008
    Location:
    Vancouver, BC
    #5
    Wow... that's very cool!
     
  6. MattSepeta thread starter macrumors 65816

    MattSepeta

    Joined:
    Jul 9, 2009
    Location:
    375th St. Y
    #6
    I was unaware that one-shot AF tracked anything, I thought that was simply in AI-Servo mode?
     
  7. miloblithe macrumors 68020

    miloblithe

    Joined:
    Nov 14, 2003
    Location:
    Washington, DC
    #7
    Do you have $20-50k for a Hasselblad system?

    http://www.dpreview.com/news/1002/10020210hasselbladh4d40.asp
     
  8. compuwar macrumors 601

    compuwar

    Joined:
    Oct 5, 2006
    Location:
    Northern/Central VA
    #8
    Continuous-servo mode focus tracks, servo mode doesn't. In continuous mode, the camera tries to follow the subject at the original point of focus, predict where it will be when the shutter fires and focuses accordingly.

    http://www.nikon.com/about/technology/core/software/caf/index.htm

    To whit:

    Paul
     

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