1. Reminder: Please user our affiliate links to get to your favorite stores for holiday shopping!

off-camera flash sync issues

Discussion in 'Lighting Forum' started by Gretsch59, Oct 16, 2013.

  1. Gretsch59

    Gretsch59 New to Mu-43

    5
    Oct 16, 2013
    When used off camera, my flash won't sync correctly when I use a zoom lens, but it works fine with a prime lens. When the zoom lens is on, the remote flash fires too early. Any ideas?

    Here's the equipment I'm using:

    Panasonic GX7
    Yongnuo YN560 III (flash is triggered wirelessly via the pop-up flash)
    Lenses: Panasonic 25mm/1.4, SLR Magic 12mm/1.6, Panasonic 14-42mm/3.5-5.6, and Panasonic 45-200/4-5.6.

    I have a sneaking suspicion it has to do with the OIS, but I'd like it if someone can confirm this or point to some other issue.

    Thanks in advance
     
  2. beanedsprout

    beanedsprout Mu-43 Veteran

    429
    Apr 13, 2013
    north central Ohio
    Strange. What happens if you flip the switch on the 45-200?

    How well does the flash work with any other cameras? Is the zoom just too long and it gets in the way of line of sight?
     
  3. Gretsch59

    Gretsch59 New to Mu-43

    5
    Oct 16, 2013
    Sorry, forgot to mention this in the original post, but flipping off the OIS switch on the 45-200 doesn't help. It's also not a line of sight issue, because in my test photos the flash is illuminated by the popup. I haven't tried any other cameras; I have a GF2, but I don't think it supports wireless off-camera flash.
     
  4. RobWatson

    RobWatson Mu-43 Hall of Famer

    2nd curtain works?
     
  5. jloden

    jloden Mu-43 Hall of Famer

    May 15, 2012
    Hunterdon County, NJ
    Jay
    That's really bizarre, zoom or prime lens should have nothing to do with optical flash triggering.

    Some questions to help figure out what's going on here:

    1) What mode is your YN-560 III in? If you're triggering it as an optical slave it should probably be in S2 mode (ignores the pre-flash for TTL)

    2) What flash mode is the GX7 in?

    3) Does it work with the 14-42 attached instead of the 45-200?

    4) Are you 100% sure the flash isn't firing at all? Look at the flash unit itself when you trip the shutter, make sure it's not firing late or something like that.

    5) Try it with the GF2. S1 or S2 modes are optical triggers on the Yongnuo flash and ANY flash unit can fire it, including the one in the GF2.

    Note that you don't need the wireless flash support on the camera, as that's only for passing along TTL information when triggering a remote flash that supports the MFT TTL protocol.
     
  6. kenyee

    kenyee Mu-43 Rookie

    13
    Oct 13, 2013
    It's probably the preflash on the popup triggering the optical eye on the external flash. The popup fires twice.

    Stop doing it that way and buy a set of wireless radio triggers...
     
  7. Ned

    Ned Mu-43 Legend

    Jul 18, 2010
    Alberta, Canada
    You don't need to go radio to avoid pre-flash, just don't use TTL metering or the Remote Commander! This isn't a radio vs optical problem, this is a manual vs auto (metering and communication) problem. Set your flash to manual flash power, like 1/64th power or a Guide Number, and all your problems will go away.
     
  8. jloden

    jloden Mu-43 Hall of Famer

    May 15, 2012
    Hunterdon County, NJ
    Jay
    Definitely possible, which is why I asked which mode he's using on the Yongnuo. The S2 mode ignores the pre-flash so that should work better in most cases.

    I like radio triggers too, but you don't *need* them, the optical triggering should work fine if it's configured correctly.
     
  9. Gretsch59

    Gretsch59 New to Mu-43

    5
    Oct 16, 2013
    Ok I'm getting really frustrated with this whole thing now (not by the responses, but by the equipment). The flash is in S2 mode.

    The only time I can get the camera to consistently sync correctly with the 560 is with the camera in wireless mode and a prime lens attached. It will also work sometimes when the camera is in TTL, but never in manual, no matter what power I have the popup set at. I understand that any flash should trigger the 560, but it's just not working that way. With a zoom attached, the flash NEVER syncs correctly with the camera, no matter what mode the popup is in (TTL, Manual, Wireless). Most of the time it doesn't even fire the 560.
    I've now tested it with my GF2, and am still getting the same spotty results. I'm about ready to give up on this working without a radio trigger. FWIW the flash works just fine when attached to the camera (both 1st and 2nd sync).
     
  10. jloden

    jloden Mu-43 Hall of Famer

    May 15, 2012
    Hunterdon County, NJ
    Jay
    Ok, what's your line of sight look like? Is there any chance the flash unit's sensor isn't able to see the flash when the zoom is attached?

    If it's triggering before the shutter then your pre-flash is triggering it - I'd turn off the TTL on the GX7 flash unit (not sure what the flash options are on the GX7 but you should have manual, TTL, and wireless?). Put it into manual mode and 1st curtain sync, then try it again.

    I'd also suggest making sure the 560 unit has its sensor pointed toward the camera and that there's a clear line of sight. Even if you have the flash unit right up next to the camera for now, just to rule that out.

    Unfortunately I don't have a GX7 or my GF2 any longer to be more specific, but I can tell you I've used a YN-560 II and 568-EX without any problems with various cameras including the GH3.
     
  11. Gretsch59

    Gretsch59 New to Mu-43

    5
    Oct 16, 2013
    @jloden:

    Line of sight is definitely not the issue. I can tell because the sensor on the 560 is illuminated by the popup in all the test images I've been taking.
     
  12. jloden

    jloden Mu-43 Hall of Famer

    May 15, 2012
    Hunterdon County, NJ
    Jay
    If you're in S2 mode with clear line of sight, and GX7 is set to manual flash 1st curtain, I don't know what else to suggest. Do you have any other flash units to play with for testing or just the one?

    Is the RX mode disabled on the flash?

    How far away are you from the remote flash? Are you testing with it right up next to the pop-up flash to eliminate distance, reflections, etc.?
     
  13. Gretsch59

    Gretsch59 New to Mu-43

    5
    Oct 16, 2013
    I have an SB-800 at work that I can try. Hopefully that will eliminate the camera as the cause. Thanks for all the suggestions.
     
  14. jloden

    jloden Mu-43 Hall of Famer

    May 15, 2012
    Hunterdon County, NJ
    Jay
    That should definitely help. I'd try optical triggering the SB800 and also try using the SB800 to trigger the YN-560 and see if that works. Good luck!