Olympus engraving the LIE on their lens barrels now

Discussion in 'Digital SLR' started by Rich, Feb 2, 2011.

  1. Rich

    Rich Guest

    The equivalency lie, that 300mm at 4/3rds = 600mm on 35mm. This did
    have some validity, when 35mm sensors were confined to the SAME PIXEL
    count as Olympus (12) megapixel, but the idea that 4/3rds at 12
    megapixels is = 35mm at 18-24mp (where they are now) is pure B.S.
    Forget the ISO performance, and the DR, the resolution is no longer
    comparable on a 2x basis as they are claiming. Give it up, Olympus.

    Rich, Feb 2, 2011
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  2. Rich

    shiva das Guest

    I thought you hated the Chinese.

    Please point out where in this description of equivalent focal length
    resolution, ISO sensitivity, or anything else other than focal length
    and sensor size affect effective focal length:

    "In photography, the 35 mm equivalent focal length is a measure that
    indicates the angle of view of a particular combination of a camera lens
    and film or sensor size. The term is useful because most photographers
    experienced with interchangeable lenses are most familiar with the 35 mm
    film format.

    "On any 35 mm film camera, a 28 mm lens is a wide-angle lens, and a
    200 mm lens is a long-focus lens. However, now that digital cameras have
    mostly replaced 35 mm cameras, there is no uniform relation between the
    focal length of a lens and the angle of view, since the size of the
    camera sensor also determines angle of view, and sensor size is not
    standardized as film size was. The 35 mm equivalent focal length of a
    particular lens­sensor combination is the focal length that one would
    need for a 35 mm film camera to obtain the same angle of view.

    "Most commonly, the 35 mm equivalent focal length is based on equal
    diagonal angle of view.[1] Alternatively, it may sometimes be based on
    horizontal angle of view. Since 35 mm film is normally used for images
    with an aspect ratio (width-to-height ratio) of 3:2, while many digital
    cameras have a 4:3 aspect ratio, which have different diagonal-to-width
    ratios, these two definitions are often not equivalent."
    shiva das, Feb 2, 2011
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  3. Rich

    RichA Guest

    "No uniform relation." Exactly! So where does OLYMPUS get off
    pretending their 4/3rds sensor is = to 1/2 the focal length on a 35mm
    sensor? I'm looking at an old Olympus P&S. The lens says,
    6.6-19.5mm. No where does it pretend it is the same as a (for
    example) 28-75mm lens on a 35mm sensor size camera. If it did try
    that, it would say, 28-75mm. In fact, the diagonal angle isn't what
    Olympus is trying to confuse people about (why brag about not being
    able to go to as wide an angle as 35mm?), they could care less about
    that. They are pretending that they achieve the effect (resolution)
    of a doubling of focal length of a lens, relative to the resolution of
    a 35mm sensor with the same lens. This only works (loosely) when both
    sensors have the same megapixel count. Since there are now 35mm
    sensors that have far greater pixel counts than Olympus's now standard
    12mp, the equivalency comparison fails when compared on the basis of
    linear resolution, which is what Olympus is using as a marketing ploy.
    RichA, Feb 3, 2011
  4. Rich

    John A. Guest

    Determining how many pixels you get per degree in the field of view,
    and how much of the field of view you can capture in a shot, are
    dependent on a number of factors. The focal length is one. The size of
    your sensor or exposed film area is another. All they are doing here
    is saying "this is an XXmm focal length lens. On our crop sensors
    you'll get a field of view that's about as wide as you'd get with a
    YYmm lens on a 35mm film camera." Basically they're factoring in the
    crop factor for you so you don't have to do the math in your head
    yourself and you can shop a little faster.

    Those basterds!!
    John A., Feb 3, 2011
  5. Rich

    shiva das Guest


    Saying that resolution or number of pixels affects angle of view is like
    saying that film speed affects angle of view.

    You are saying that if I have a roll of Tri-X in my Nikon F2 with a 50mm
    lens attached it will have a different angle of view than if the camera
    had a roll of Plus-X in it. Nope.

    Angle of view depends on focal length and film/sensor size. Period. You
    may not like it, but that is another subject. You are certainly free to
    not buy anything made by Olympus. But to say that their labeling lenses
    with real and effective focal lengths is lying is going a bit too far.
    shiva das, Feb 3, 2011
  6. Rich

    Paul Furman Guest

    And the noise performance is another. I've not seen those few relevant
    factors put together in a simple summary, though it wouldn't be all that
    hard. The results would still leave you to choose which performance
    factors suit your needs - there is no single best spec.

    -noise at pixel level for various ISO settings
    -field of view and available lenses with suitable resolution
    -automation features
    Paul Furman, Feb 3, 2011
  7. Rich

    Bruce Guest

    DxO Labs gives an overall image quality rating to camera bodies which
    would include the first two items on your list. It provides a valid
    comparison between different formats because smaller sensors with the
    same number of pixels tend to generate more noise. The second two
    items are to a great extent subjective.
    Bruce, Feb 3, 2011
  8. Rich

    bugbear Guest

    Give it up, Rich.

    bugbear, Feb 3, 2011
  9. Rich

    bugbear Guest


    Further, quite a lot of EXIF files (from many brands)
    do the same calculation; if they don't some exiftool
    reader will do it for you, resulting in a field labelled
    "35mm equiv length" or something like this.

    The effect of focal length on a 35mm negative is part
    of current "cultural intinct" in photographers;
    people "just know" what a 80mm lens *does*.

    You can tell this by the stark confusion when a habitual
    35mm photographer first encounter medium (or larger) format
    cameras, and looks at the focal lengths of the lenses.

    I note that DPReview lists lenses of P&S
    camera in 35mm equivalent lengths, presumably
    for reader's convenience, unless they're
    part of the "Olympus conspiracy"

    bugbear, Feb 3, 2011
  10. Rich

    Mike Guest

    Following that logic no lens manufacturer would dare put and focal range
    on their lenses as who knows what the pixel count or even the size of
    the sensor (in some cases) they would be paired with either now or in
    five years time.

    Most P+S cameras are advertised with some reference to the equivalent
    35mm optical range and this is essential because of the varying senor
    size etc.

    Mike, Feb 3, 2011
  11. Rich

    Peter N Guest

    He can't. Rich is so full of hate that he can't help himself.
    What a shoddy existence.
    Peter N, Feb 3, 2011
  12. Rich

    Paul Furman Guest

    Yep, maybe not that easy either.
    Paul Furman, Feb 3, 2011
  13. Rich

    Rich Guest

    Have you morons ANYTHING substantive to add?
    Rich, Feb 3, 2011
  14. Rich

    George Kerby Guest

    That you need some Anger Management classes?
    George Kerby, Feb 3, 2011
  15. Rich

    Savageduck Guest

    Did you ever find who it was who pissed in your crib when you were a baby?
    Savageduck, Feb 3, 2011
  16. Rich

    Peter N Guest

    Did you really expect factually based statements derived in a reasoned
    and logical fashion?

    He has never responded to a direct question yet, without trying to side
    step the issue.
    Peter N, Feb 3, 2011
  17. Rich

    RichA Guest

    You people are beyond stupid and in DIRE need of a basic course of
    optical theory.
    RichA, Feb 4, 2011
  18. Before aspiring to even consider optical theory, you need a course on
    basic geometry! What is the ratio of heights of similar (ie. having the
    same internal angles) isosceles triangles if the base of one is half
    that of the other?

    Note that the unit of measurement of the base, whether miles,
    centimeters, pixels or parsecs, does not change that scale factor!
    Kennedy McEwen, Feb 4, 2011
  19. Rich

    bugbear Guest

    To your OP?

    Why try to polish a turd?

    bugbear, Feb 4, 2011
  20. Have you anything substantive to post in the first place? I didn't think
    Pete Stavrakoglou, Feb 4, 2011
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