580EX in manual mode and 1/8000s

Discussion in 'Canon EOS' started by dcheung, Aug 22, 2006.

  1. For some reason, when I put my 580EX in manual mode while connected to my camera
    via hot shoe directly, my shutter speed goes to 1/8000th of a second.

    Is this supposed to happen? Does this happen with yours?
     
  2. No it is not supposed to happen. Moreover the 580EX will definitely not sync at 1/8000s !
     
  3. WHat mode is your camera in? I've seen this somewhere on this board before. I think it happens when certain camera/flash combinations and MIGHT be explained in the book. Sorry its been a while since I saw the thread, so I'm a fuzzy on the details.

    m
     
  4. You're in Av mode. Try M mode instead. The other option is to turn off HSS and then the shutter speed will go to 1/250.

    It surprised me the 1st time I tried it also, but I found that it was the same across all my EOS cameras, film & dslr. The 420EX is the same.
     
  5. I have never observed this phenomena (I have a 550EX and have used manual flash on occasion) but if you will explain your set up then maybe we can try and duplicate it.

    Are you using high speed sync mode ? What camera mode are you in ?
     
  6. Alistair... read my post. Av mode, HSS on and put the flash in manual mode and the camera (20D & 350D) will go to the highest shutter speed.

    You may also have to set your flash sync in Av to "auto" under the custom functions on the camera.
     
  7. OK. I owe you an apology. It is "normal". I checked. I guess I never used high speed sync together manual flash before.

    In Av mode you do get 1/8000sec for the shutter speed. Furthermore in Tv mode I always seem to get the smallest possible aperture. This seems unaffected by any of the flash CFs.

    The flash manual suggests you should set the mode to either Av or M (since Tv gives you the smallest aperture and hence a diffraction softened image). If you use the 1/8000 sec and the distance guide on the back of the flash you do get correctly exposed flash pictures.

    With the flash in manual mode the camera defaults to the flash being the only source of illumination ! It does not do fill of any kind. In fact I sometimes use the flash on M for fill/catchlights (no preflash) but normally I switch the camera to M mode when shooting with flash.
     
  8. I read your post Kin Lau but the original poster did not say he was using high speed sync mode (or I would have been more circumspect with my answer). I was just trying to confirm that this was the case.

    Incidentally changing the Sync in Av CF from Auto to 1/250s doesn't do anything.
     
  9. Alistair, I know the poster didn't mention it (he didn't mention Av mode either), but I noticed the same thing a few weeks ago, so I know exactly how he got it.
     

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