Anybody have a Vivitar Zoom Thyristor 3500 flash with DM/C module?

Discussion in 'Digital Photography' started by Peabody, Apr 5, 2011.

  1. Peabody

    Peabody Guest

    I was given one of these today, but can't find a manual anywhere.
    This doesn't look promising for off-camera flash because in Manual
    mode there is no power adjustment. But as an automatic thyristor
    flash, it might actually work on-camera as a poor man's TTL.

    First things: I measured the voltage between the center contact
    and the shoe shell contact, and it's 9.5V on my R/S meter, which
    reads a bit high. So probably 9V. Does that sound safe for a Canon

    I assume the "DM/C" module means it fit FD, or whatever the Canon
    film camera flash standard was in the early '80s. It has two
    contacts in addition to the center contact. So I assume the XT
    would treat it like a manual flash.

    The flash has three manual zoom settings - W, N, and T. But there
    are two other settings. One sets the ASA (25 to 800), and the
    other selects between M(anual) and one of three colored dots -
    orange, green and red. I believe the dots are related to the
    thyristor function, but I don't know in what way.

    Also there's a green LED that lights up for a second when I trigger
    the flash in any of the dot settings, but not in M mode. I'm not
    sure what the LED indicates.

    Well, if anyone has any explanations, or a link to the manual, or
    warnings, please post a response. Thanks very much.
    Peabody, Apr 5, 2011
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