why does wide angle end of zoom gets cut on slightly upgraded model?

Discussion in 'Digital Cameras' started by peter, Dec 21, 2004.

  1. peter

    peter Guest

    Canon powershot A85: wide 35mm, sensor size 1/2.7 inch

    Canon powershot A95: wide 38mm, sensor size 1/1.8 inch

    This doesn't make sense. When the CCD size is increased, if they leave the
    lens alone, the wide angle end of the zoom should go even wider. But
    instead, they made it less wide than before. What gives?

    Here's another example:

    Fujifilm finepix E510: wide 28mm, sensor size 1/2.5 inch

    Fujifilm finepix E550: wide 32.5mm, sensor size 1/1.7 inch

    This is really a pity because I like the larger CCD size and I also like
    wide angle :-(
     
    peter, Dec 21, 2004
    #1
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  2. It's probably cheaper. They won't "leave the lens alone" as it wouldn't
    cover the full image circle of the bigger sensor at the quality they need,
    so it is likely a new lens design.
    Take a look at the Nikon 8400 - 24mm wide-angle.

    David
     
    David J Taylor, Dec 21, 2004
    #2
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  3. More likely, the A85 uses the same lens from the A75 and A70, which are
    its predecessors, all with 1/2.7 inch sensors. The A95 probably uses
    the same lens as the A80, both having 1/1.8 inch sensors.

    The one sensor is 1.5 times larger than the other. Thus, the "ideal"
    lens to match one has 1.5 times greater focal length at the wide and
    tele ends, 1.5 times the image circle diameter, but 2/3 the limiting
    resolution of the lens needed for the other sensor. A single lens
    wide enough for the larger sensor would be too long for the smaller,
    and wouldn't have enough resolution either.

    In comparison, the difference between 35 and 38 mm effective coverage
    is only 8%. That's pretty close, despite the sensor size difference.

    Dave
     
    Dave Martindale, Dec 24, 2004
    #3
  4. Thanks, Dave. I'm not familiar with the intimate history of the Canon
    range....

    David
     
    David J Taylor, Dec 25, 2004
    #4
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