Question about Canon EF 180mm f3.5L Macro USM AutoFocus Telephoto Lens

Discussion in 'Canon' started by Dave, Nov 2, 2007.

  1. Dave

    Dave Guest

    Reviews often speak of this lens as an excellent telephoto lens.
    I guess I'm rather ignorant about the lens specs:
    * Lens Type: teleconverter
    * mounting_type: Canon EF
    * Camera Magnify Power: 1 / 1
    * lens_system_special_functions: Macro
    * maximum_aperture_range: F/3.5
    * Minimum focal length: 180 millimeters
    * min_focal_range: 18.9 inches
    * Focus Type: auto-focus, manual-focus
    * Real Angle Of View: 13.5
    * Weight: 2.4 pounds
    * Item Display Diameter: 3.3 inches
    * Length: 7 inches

    Zoom is often referred to as 6X, 10X etc. Can anyone tell me what X would
    this be equivalent to?
     
    Dave, Nov 2, 2007
    #1
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  2. Dave

    Matt Ion Guest

    With cameras, the "X" is a ratio of the shortest to the longest zoom;
    it's not a power of magnification like with binoculars and telescopes.

    A 70-210mm zoom lens would be 3X (210/70). A 28-300 would be 10X
    (approximately - 300/28 = 10.714285714285714285714285714286 to be
    precise). The actual magnification will depend on the size of the
    sensor (or film frame, if applicable).

    As others have noted, since this is not a zoom lens, but a fixed focal
    length, the actual zoom would be "1X".
     
    Matt Ion, Nov 2, 2007
    #2
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  3. Dave

    Dave Guest

    Thanks all! How would I figure the minimum distance from the front of the
    lens to the subject that would be possible to obtain focus?
     
    Dave, Nov 3, 2007
    #3
  4. Dave

    Matt Ion Guest

    18.9 inches, according to your listed specs...
     
    Matt Ion, Nov 3, 2007
    #4
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