Digital Rebel: Weird Aperture-Priority Flash Behavior

Discussion in 'Digital Photography' started by Larry R Harrison Jr, Oct 21, 2004.

  1. I just made a deal for a 300D and have been looking forward to it, but....

    When I had the Nikon N80 and even the N65 (which is more "crippled" than the
    N80 is), aperture-priority was the mode to use for flash. Makes
    sense--shutter-speed is a non-issuse since it belongs at or near X-sync,
    aperture is the variable that matters. So I shot in aperture-priority mode
    and change apertures as I saw fit (of course, I wouldnt' shoot at f/16 from
    200 ft away with 50-speed film or whatever). The shutter speed, meanwhile,
    would remain at or near X-sync unless I had the camera in "night" or
    "slow-sync" mode.

    The 300D in aperture-prority seems to assume slow-sync, with no way around
    it. I was trying one out in the store and I couldn't believe how slow the
    shutter speeds it was giving me. (Yes, I distinctly DID have the pop-up
    flash up.) I also couldn't believe how as I closed the aperture down it kept
    giving even slower shutter speeds. Even when I focused on something close
    with no far-away backgrounds I still got this.

    On the other hand, in the Full Auto or P mode, it used 1/60 second--but then
    I can't change its aperture.

    Is there anyway around this besides the "M" mode, which is relatively
    awkward? Does the Russian Hack address this? And why in the world would it
    be setup to do this in the 1st place? (I know, go ahead--tell me, this is
    why the Nikon D70 is way better. Believe me, I prefer it myself.)

    Larry R Harrison Jr, Oct 21, 2004
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  2. Okay, I got an explanation. The camera is designed to do this to allow for
    ambient light instead of allowing black backgrounds.

    I'd rather it not do that. I'd rather it do like the Nikons do--keep the
    shutter speed at or near X-sync and STILL manage to balance ambient-light
    with it via the 3D Matrix system (or E-TTL in Canon's case), and only allow
    large dips in a "slow sync" flash mode. Oh well, I guess that's why a lot of
    people prefer the D70 (I don't blame them).

    There are two ways around it. One, install "The Hack" and enable CF 3 to a
    value of 1 (its default is 0). This fixates the shutter-speed to 1/200
    second in Av (Aperture-Priority) mode. The other is to use M (manual) mode
    whereby you can then of course set any aperture/shutter speed you so choose
    (below 1/200 of course). That's fine with me except (a) having to use the +-
    AV button on the back to change apertures (I'd be inclined in a hurry to
    forget and inadvertendly change the shutter speed instead) and (b) I'm not
    sure if the metering mode changes from E-TTL flash to regular "classic" TTL
    flash the way my Nikons used to do (they'd disable Matrix or 3D Matrix flash
    and use "classic" TTL flash).
    Larry R Harrison Jr, Oct 22, 2004
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  3. Larry R Harrison Jr

    Matt Ion Guest

    Actually, the Digital Rebel will sync up to 1/200 with the internal
    flash. The following chart is included in the manual (it won't line up
    right if you use a proportional font):

    P Auto (1/60 to 1/200) Auto
    Tv Manual (30 to 1/200) Auto
    Av Auto (30 to 1/200) Manual
    M Manual (Bulb to 1/200) Manual
    A-Dep Auto (1/60 to 1/200) Auto

    However, the previous page includes this tidbit that should answer your

    "Select <Av> mode to manually set the aperture value. Against dark
    backgrounds such as the night sky, slow-sync shooting will be set so
    that both the subject and the background are exposed correctly. The
    main subject is captured by the flash, and the background is captured by
    long exposure using a slow shutter speed. (Because automatic slow-sync
    shooting uses a slow shutter speed, always use a tripod.)"

    In short, slow-sync IS specifically used in aperture-priority, *when the
    background is dark*. This would generally include the interior of most

    BTW, the EX-series Canon Speedlite dedicate flashes will sync up to the
    maximum shutter speed of the camera, as well.
    Matt Ion, Oct 22, 2004
  4. Hmm, sorry for the post, I seem to have answered my own question.

    The Russian Hack does indeed address this, which apparently is an issue. (It
    sure is an issue for me, why in the world would it shoot at 1/4 second at
    f/8 with the flash? Please, that's stupid.) "The Hack" of course re-enables
    many of the CF features of the 10D, and apparently one of them is about this
    very thing.

    CF3 has a default value of 0 which allows the shutter speed in Av mode to be
    whatever. Change this to 1, though, and it locks it down to 1/200 second.

    Okay, so the background will be black. At least I can control what I want it
    to do now.

    Larry R Harrison Jr, Oct 22, 2004
  5. Larry R Harrison Jr

    Matt Ion Guest

    Even if it did that, you'd have to set a slow shutter to balance ambient
    light indoors. Most malls I've been in, you'd have to use 1/60 or
    slower at f/4 on anything under ISO 200 to get anything recognizable in
    the background (not to mention, weird things happend when shooting
    faster than 1/60 under most types of broad indoor lighting, such as
    flourescent, because of the power-frequency flicker).
    Matt Ion, Oct 22, 2004
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