Problem with 20D built in flash?

Discussion in 'Canon EOS' started by dan_woodlief|1, Dec 11, 2004.

  1. I just got a new 20D a week ago. Last night I was playing around with
    it and was focusing on something that was too close. I had the built
    in flash up. The flash was giving a series of rapid bursts, and it
    sounded very strange, an electrical sound, almost like a short. It
    happens everytime I repeat this. Has anyone else experienced this? Is
    it normal, or does this sound like an electrical problem? I plan to
    contact Canon about it on Monday, but would like to hear from others
    first. I really want to be able to return it to B&H and get another
    in time for Christmas if I have a problem. Thanks.
  2. Dan, Is it possible you're pressing the DOF button, located beside the lens? That will cause the camera to emit what you describe - it's the modeling light feature. Good luck!
  3. I only pushed the shutter button. This could very well have been the modeling light, but does it usually make a sound like that?
  4. It's Canon's idea of AF assist. Annoying, isn't it?
  5. That's normal. It's the 20D's pop-up flash going into autofocus assist mode by flashing stroboscopically. If you have a Canon shoe-mount flash like the 550EX or 580EX, it will do the same thing when you press the depth-of-field preview button. But in that instance, it's the hotshoe flash going into modeling light mode.
  6. It's AF assist. If you have a shoe mounted flash with built in IR AF assist (i.e. most speedlites), that will overide the annoying popup flash strobing.

    I believe the flash only pops up and does this in the so called "idiot modes" (or "program modes"). In the creative modes you have to pop it up manually if you want to AF in darkness.

    I'll bet it's in the manual if you look hard enough.
  7. Yep - middle of page 68, and the foot of page 93.
  8. And YES the sound is normal, electronic flash units generally go from loud to very loud, if you listen to them. Theres generally a few thousand volts going into the flash tube, so as it breaks out of the switch (capacitor) you can hear it. (OK not technically the correct language, but the story's true).
  9. Luckily this can be switched off via a custom function. My 50/1.8 focuses fine in low light but the camera will use the built in flash for AF assist. I have the camera set for AF assist only with external flash.
  10. I appreciate all the responses. I didn't see it in the manual, but I guess I just missed it. I wasn't surprised by the flash, only the noise. I have been using EOS cameras for years and had never heard it like that before. I guess the conditions were never quite right for me to hear it. I rarely use the pop up flash inside. Thanks for easing my mind.
  11. With the 20D (and 10D), it's even easier: just select the Flash Off mode.

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