HyperSync / HSS with the V6 (without dedicated equipment)

edited May 2016 in V6 Questions
Often HSS (or HyperSync) requires dedicated (i.e., brand-specific equipment) in order to obtain the required pre-sync signal for off-camera flashes.

Here's a simple way to achieve exposure across the full frame when using shutter speeds higher than the sync speed without any dedicated equipment that we could refer to as the "starter pistol method":

One needs

[A]: 1 x V6/V5 (in transmitter mode) to act as a trigger for both camera & flash(es)
[B]: 1 x V6/V5 (in receiver mode) as a remote trigger to trigger the camera
[C]: 1 x camera triggering cable
[D]: N x V6 (in receiver mode) (or RF60) for off-camera flash(es)

The simple "trick" is to set a delay on all off-camera V6 attached to flashes (or on all RF60) [D] that corresponds to the shutter lag of the camera.

Once that is done, one can fire both camera (through [B]&[C]) and remote flash(es) [D] at the same time with the off-camera trigger [A]. If the delay value is chosen correctly, the triggering of the flash(es) [D] will coincide with the exposure of the frame.

Note that all shots have to be taken with the off-camera V6 [A]. Using the shutter release button on the camera would not give the off-camera flashes the advance warning.

On my Pentax K-5 II and an FA 43/1.9 at f/8 and 1/500s shutter speed, I could consistently illuminate the whole frame when I set an off-camera RF60 to a delay of 91ms. 

This technique will work with any flash when using 1/1 "full power", i.e., using the "HyperSync" technique, as a full power pulse is long enough to illuminate all of the frame.

With an RF60 set to "HSS" mode, however, even flash powers less than "1/1" are possible, and the frame illumination will be even (rather than graduated as is unavoidable with the above "HyperSync" technique).


  • Hi Class A,

    Any "easy" way to find the right delay for a specific shutter speed ?

    Regards ;-)
  • Hi novsky,

    in the context of shooting at shutter speeds higher than the sync-speed, the shutter speed does not influence the correct delay value. It only influences the height of the shutter curtain slit that travels over the sensor, but I'm pretty sure it does not influence when the travelling starts and stops.

    The delay depends on the shutter lag of your camera and a little bit on the chosen aperture (smaller apertures take longer to establish as the aperture blades have to move for longer).

    Once you found the right ballpark, adjusting the delay up or down will move any black bars in and out the frame, so it only takes a couple of tries to fine-tune.

    Getting in the right ballpark can be more involved. You could try to look up the shutter lag for your camera. The published value for the K-5 II (91ms after focus has been obtained), coincides precisely with the value that I ended up using. Note, however, that shutter lags hugely depend on the mode (AF vs MF, metering, stand-by, etc.) so you need to find the right figure for your respective mode.

    The RF60 manual provides starting points for popular camera brands and you can also just start with something plausible and jump in increments of 3 or 5 milliseconds. If the jumps are not to big, you won't miss the value range in which the flash can actually contribute to the exposure, i.e., when it is neither completely too early or completely too late.
  • Hi Class-A

    Many thanks for your detailed answer ;-) I will try asap for portraiture.

    It seems that i'm not ready to shoot some sport in hss with my Pentax :-/
  • Thx again Class-A, after a few tests i can start playing hss under full sun => K3+70/200 at 2.8 with a delay about 94ms, it seems to work as expected even if i change freely speed/aperture from f2.8 to f8 from 1/180 to 1/8000.
    That seems to be not so hard to accomplish outdoor for sport, macro or portraiture with highspeed/sync

    So many thanks for that issue ;-)
  • No worries. :) Cool that you apparently found a delay time that seems very versatile!
  • Nice to find this thread.

    I own a 645z, hss works fine with my 540II Pentax flash.
    I also own profoto b1 flashes and a profoto canon remote, allowing to do hss if attached to a canon.

    Would I be able to trigger the profoto hss trigger if attched to a cactus receiver? and then get to trigger the b1 in hss mode?

    I also wonder if the pentax will trigger the cactus when set shorter then 1/125s. normaly if no hss device is attached, it will stop to send the signal to the flash.

    best regards

  • I don't think you can use the Profoto HSS functionality unless you use their Air Remote units connected to a Nikon or Canon.

    The approach I described only works when you either

    a) can activate the HSS strobe functionality manually (like with an RF60), or

    b) use the HyperSync approach, i.e,. utilise the fact that a single flash can be long enough to illuminate the whole frame. Many studio flashes increase their illumination times, the lower you set the power. With speedlights (or IGBT-based strobes), it is the other way round.

    Regarding your trigger signal question: Yes, if the shutter speed exceeds 1/125s on your 645z then the camera won't generate a trigger signal anymore. However, the "trick" I described in my original post works around that. It does not need a hot-shoe trigger signal because it fires the strobes/flashes at the "same" time it fires the camera (just with a small delay).

    P.S.: The Priolite system supports HSS for your 645z natively, but IIRC, they are using long pulses (i.e., HyperSync) rather than extended bursts (typically referred to as "HSS").
  • Hi Class A,

    I just came across your post. I'm following most everything but I have one question.

    Why do we need a camera triggering cable [C] as well as a V6 [B] to trigger the camera? Wouldn't the V6 trigger the camera without the cable?

    I'm fairly technical but sometimes my mind snags :)

  • Hi bigmike01,

    the only chance for a V6 ([B]) to release the shutter on a camera is through a shutter release cable ([C]).

    If you simply attach a V6 to the hot-shoe of a camera, the V6 won't be able to make the camera take a shot.

    Note that with the technique I describe, you have to take a shot by pressing the test button on the V6 Tx ([A]). You can no longer use the camera shutter release button to take a shot (as that would not give advance notice to the off-camera flashes).
  • Ahh gotcha. The hotshoe is one-way, duh (it wouldn't make sense to have it go both ways as it was originally designed).

    Thanks for clarifying! I guess, depending on how one shoots, you'd have to get a feel for using the V6 "release" rather than the camera release.
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