2nd curtain with EM5 flash(confused)

Discussion in 'Lighting Forum' started by felicedenigris, Nov 7, 2013.

  1. felicedenigris

    felicedenigris New to Mu-43

    8
    Oct 7, 2012
    I'm learning to use flash with my Olympus EM5 with the stock flash and with a Metz flash for Olympus and Panasonic cameras. I am learning the basics of flash with this camera for the first time. Well my question is "Why when I use 2nd curtain, does it fire once, in the beginning and again at the end?" , shouldn't it just fire at the end? I thought 2nd curtain is like rear curtain and only fires at the very end. Not the beginning and the end. I noticed 2nd curtain fires twice with my Metz and with the stock flash that comes with EM5.
     
  2. darosk

    darosk Mu-43 Top Veteran

    705
    Apr 17, 2013
    Kota Kinabalu, Malaysia
    Daros
    I believe the first flash is a pre-flash so the camera can measure exposure.
     
  3. felicedenigris

    felicedenigris New to Mu-43

    8
    Oct 7, 2012
    Hmm. Thanks for the reply

    Thanks darosk , So is the first flash just measuring exposure and not affecting the lighting of the photograph?
     
  4. darosk

    darosk Mu-43 Top Veteran

    705
    Apr 17, 2013
    Kota Kinabalu, Malaysia
    Daros
    Yup. The sequence is:

    shutter button press -> Pre-flash -> Shutter opens -----> Flash -> Shutter closes
     
    • Like Like x 1
  5. felicedenigris

    felicedenigris New to Mu-43

    8
    Oct 7, 2012
    Ok Clear Now

    Thanks , that's very clear to me now.
     
  6. klee

    klee Mu-43 Veteran

    367
    Mar 20, 2013
    Houston, TX
    Kevin
    I'd like to throw my question into the ring also... with 2nd curtain and slower shutter speeds like 1/60, I'm not getting what I expect.

    When an object is moving from left to right, it blurs horizontally and the flash should freeze the object somewhere in the blur according to when it was fired.

    But with 2nd curtain flash on my EM5 , I notice that the frozen motion is on the left most portion of the motion, not the right most.
    I was expecting the flash to freeze the object after it had left a tail behind it.

    (does any of that make sense? I find this hard to explain without a photo on hand)
     
  7. felicedenigris

    felicedenigris New to Mu-43

    8
    Oct 7, 2012
    Same problem

    This is what I am ultimately trying to do. Your explanation makes sense, but I have come across the same issue and I was wondering If anyone else has. Unfortunately I can not answer your question but I hope someone can.
     
  8. Ross the fiddler

    Ross the fiddler Mu-43 Hall of Famer

    Ideally you set a slower shutter speed (in Manual or Shutter Priority) to actually see blur in the image (e.g. walking out with a birthday cake with lighted candles) & the 2nd curtain flash (Slow 2) should freeze the image at the end of the exposure time. In other words, the flash light should light the end of the walk with the cake with the light of the candles trailing behind, not the beginning.

    Klee, maybe the exposure time isn't long enough. Doing it in Manual allows the desired shutter speed (to cover the right amount of blur distance) & aperture (which might need to be closed down a fair bit) to be used. I just tried it with my FL50R flash on my E-M5 where it works fine for 1 sec & f/22. And another thing, set the ISO at 200 too (not Auto).
     
  9. darosk

    darosk Mu-43 Top Veteran

    705
    Apr 17, 2013
    Kota Kinabalu, Malaysia
    Daros
    I'm in agreement with Ross, it's possible 1/60th may not be slow enough to see trails? TBH I haven't used rear sync flash in years - I did a very brief stint shooting for a club in L.A., and I was 1/2 second shutters (and thereabouts) with success.

    Try fiddling around with settings and experiment. Also, it bears stating that how fast the subject is moving affects how much you need to drag the shutter to start seeing 'trails'.
     
  10. Ross the fiddler

    Ross the fiddler Mu-43 Hall of Famer

    I haven't used it much either but used to do it occasionally with my Pentax SF7 film camera & dedicated TTL flash with tilting & swivelling head.