Canon 550EX and 420EX Wirless Mode and also Umbrella/Softbox Use

Discussion in 'Canon' started by Matt, Nov 18, 2004.

  1. Matt

    Matt Guest

    Does the 550EX and 420EX wireless mode work from the flash from the built in
    flash on a 20D? Or are they 'truly wireless?

    If they are triggered by the camera flash, does that mean that if the flash
    is facing an umbrella/softbox behind you(ish), it may not fire?
    Matt, Nov 18, 2004
    1. Advertisements

  2. Matt

    Eric Miller Guest

    Does the 550EX and 420EX wireless mode work from the flash from the built
    No, they are not triggered by the built-in flash on the 20D.

    Yes, they are truly wireless and would be so even if they were triggered by
    the built in flash, as long as they aren't triggered by wire.

    The 550ex and 420ex are triggered by infrared signals emitted by either a
    550ex or a Canon ST-E2 flash transmitter and either method works pretty
    As stated above, they aren't triggered by the camera flash, though it might
    be possible to make them triggered by the camera flash with additional
    equipment (but the 550ex will only fire once if triggered by some optical
    slaves and then you will have to physically separate the 550ex from the
    optical slave to make it fire again!). When the ST-E2 transmitter is used,
    the 550ex and 420ex only seem to work in E-TTL mode with pre-flash and all
    ( a bummer if you are trying to remotely trigger these two flashes to shoot
    hummingbirds, but as you can see in this link Hummer 2.htm, it
    isn't impossible.That shot was done with one 550ex and one 420ex, both in
    front of the camera and controlled with an ST-E2 transmitter on a Canon 10D.
    Luckily, the bird didn't flinch at the E-TTL pre-flash like some of the
    birds in the other photos on my site.

    Canon states that the flashes can operate from bounced signals indoors so it
    may be possible to put the flashes behind the camera. Additionallyk, there
    may be brackets or off-camera dedicated cords that will allow you to point
    the infrared transmitter on the ST-E2 or 550ex at the slave flashes behind
    the camera. However, when mounted on the camera, the transmitters on both
    the 550ex and ST-E2 only point directly forward. The actual flash head on
    the 550ex can be pointed in almost any direction that isn't down.

    Eric Miller
    Eric Miller, Nov 18, 2004
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.