Canon 50D Auto ISO Question

Discussion in 'Canon' started by John Sheehy, Oct 24, 2008.

  1. John Sheehy

    John Sheehy Guest

    No. It has an "auto" value for ISO, but it is programmed by morons, who
    don't seem to understand anything about how Canon DSLRs work in regards
    to ISO and noise, or about the needs of users.
    No. 50D auto-ISO gravitates to ISO 400
    No, but it doesn't go above 400 unless it really, really needs to. Even
    if you have it set to Tv-priority, it will hold the ISO down to 400 when
    it should be at 1600, which makes absolutely no sense, as ISO 400 will
    give a noisier image than 1600 when 1600 is the right ISO for the maximum
    aperture, the set shutter speed, and the lighting.

    In manual exposure mode, "auto-ISO" is fixed at ISO 400! Manual exposure
    (TAv) mode is the one where I would use a properly-working auto-ISO the

    An intelligent auto ISO should have *NO* hesitation to raise the ISO as
    necessary, at least in manual exposure mode ("TAv") and in Tv mode.
    There is no intelligence, whatsoever, in Canon's system. Whoever is
    making the decisions on auto-ISO for Canon is an incompetent moron.

    I really don't understand why so many people are interested in limiting
    the high end of ISO. My problem with Canon "auto-ISO" is that it doesn't
    go high enough.

    Do you like blurred images? Under-exposed images?
    John Sheehy, Oct 24, 2008
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  2. John Sheehy

    SamSez Guest

    Gee, my 50d goes to 1600 much more than I'd like.

    Yes, I wish it were a user set curve -- but saying it doesn't use 1600 or
    'gravitates to 400' is contrary to my experience with the camera over the
    past three weeks or so.
    SamSez, Nov 5, 2008
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  3. John Sheehy

    John Sheehy Guest

    That is only an issue here with IS enabled; the camera does not recognize
    that I can use a slower shutter speed. Otherwise, the camera is slow to
    climb the ISOs. It would be nice if the camera recognized IS as well as
    focal length, when the shutter speed is floating along with another
    My initial impression of gravity may be from failing to make a clear
    distinction between auto-ISO performance with flash enabled and disabled.

    I've never heard of you before, so I don't know how much you understand
    about ISOs, but avoiding high ISOs as an end in itself is a futile game.
    Under-exposure and blur are not necessarily superior solutions. People
    who shoot their cameras at ISO 400 with -1.3 EC, for example, are fooling
    themselves, unless they do it specifically to take advantage of 1.3 more
    stops of highlight headroom. They are getting far more noise than if
    they shot at ISO 1000, which is their actual exposure index. Lots of
    people shoot at low/medium IS, in Av-pri mode, and delete most shots
    because of motion blur.
    John Sheehy, Nov 8, 2008
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