"Wired" Sync for Slave Flash?

Discussion in 'Lighting Forum' started by scott, May 31, 2013.

  1. scott

    scott Mu-43 Veteran

    Nov 15, 2010
    I've added a slave flash to my macro setup, but very often the slave flash won't fire, because it's not getting enough light from the main flash (line-of-sight obstructed, not much reflection from the subject, etc.).

    I could go to a radio flash trigger, but it seems like an unnecessary expense and complication, given that I don't need my flashes to more than about two feet apart.

    It occurred to me that I could do just fine with a "wired" connection, but I'm not sure if it works the way I think it would. Any help would be appreciated.

    Is it really as simple as using a TTL-capable hot-shoe adapter on the main flash that also has a PC-cable port? Then I guess I'd put a generic PC/hot-shoe adapter under the slave flash, and connect the two PC ports. Is that all there is to it?
  2. Ned

    Ned Mu-43 Legend

    Jul 18, 2010
    Alberta, Canada
    If you are using a TTL-cable then you don't need PC Sync cables. PC Sync is for the single contact only, meaning manual flash. The PC Sync system is what comes in parts... you need a hotshoe adapter, flash adapter, and a PC Sync cable between them. TTL cables on the other hand, will have both ends for your flash and your hotshoe together as it is a complete system in one cable. Of course, that also means you can't swap out parts and use different lengths of cable and what not, like you can with PC Sync.

    With a TTL cable, it's just like plugging your flash into the hotshoe, except that it's a mobile hotshoe. Incidentally, you can use both Four-Thirds (Olympus or Panasonic) TTL cables as well as Canon. Canon has the exact same pin pattern as Four-Thirds, although the function of the pins are different. So as long as you're using a Four-Thirds body and Four-Thirds flash, you can use a Canon TTL cable between them. You will have better availability and choice with Canon cables, either better quality OEM cables, cheaper third-party, or different styles and lengths (including coiled, uncoiled, etc).

    PS, if you're having trouble with the optical triggering and you don't mind going into manual (personally I prefer it), you might want to try using Slave mode on your flash rather than using the Remote Commander. That is a more reliable triggering system. You can use your pop-up or another external flash on low manual power in order to trigger an optical slave.
  3. scott

    scott Mu-43 Veteran

    Nov 15, 2010
    Maybe I should explain the setup to make this more clear. The plan is to have:

    * The camera mounted on a two-arm Manfrotto flash bracket
    * The main flash on one arm, and the slave flash on the other
    * A TTL cable from the camera hot shoe to the main flash
    * An LED "focusing light" on top of the cable mount

    Now--I need something to trigger the slave flash, and optical triggering isn't reliable.

    If I:

    * put a TTL-capable hot-shoe/PC adapter between the flash end of the TTL cable and the main flash
    * put the slave flash on a generic hot-shoe/PC adapter, and
    * connect the two PC adapter ports with a PC cable...

    ...will this be enough to trigger the slave flash?
  4. RobWatson

    RobWatson Mu-43 Hall of Famer

    Why not rig a little mirror to redirect the on cam flash such that the slaves are fired optically? Otherwise just put radio triggers on everything.