Cannot trigger Nikon SB 900 from D3s using V6 II

Recently bought 2 V6 II. Set up OK and able to fire flash from either Rx or Tx test button. Also able to adjust Sb 900  Focal length and Rx power level from Tx, but cannot trigger flash from Nikon D3s camera shutter release. LED status light turns green on Tx but nothing on Rx. Also camera locks. Cannot press shutter release, unless switching camera off and then on again. Can anyone tell me what I might be doing wrong. Many thanks  


  • edited September 2016
    Does the Rx LED light up when you press the test button of the Tx while the latter is mounted to the camera?

    Reasons why the Rx may not respond include a different radio channel setting or having too little distance between the Rx and Tx unit (without engaging the "SHORT" option of the "WORK RANGE" feature on the Tx). None of these seem to apply in your case, as the Rx responds to power level changes, but your description does not entirely rule out the possibility that power-level changes and the triggering attempts happened in different scenarios, e.g., using different distances between Rx and Tx.

    I would try different sync-modes, i.e., "HSS OFF" and "POWER SYNC" in addition to "HSS NORMAL", and also shutter speeds below and above the sync-speed. If you report the results of such tests, hopefully someone can help you.

    BTW, it is a good idea to ensure that your D3s establishes proper contact with the V6II. To do that, set the camera system to "AUTO" and check whether the V6II Tx can detect "Nikon" as the camera system. You will see an "N" within the camera symbol upon start up, if that is the case.

    Make sure to have the camera "awake" when turning on the V6II, e.g., by tapping on the shutter release button while you turn on the V6II.
  • Regarding your comment in para 4, I tried setting the V6 II to AUTO to check whether it could detect my Nikon D3s as the camera system and it could not! The camera system box on the LED screen showed blank. Does that mean that V6 II does not support my camera type, or what? I have double checked by plugging my sb - 900 flash directly onto my camera and all functions appear to be working OK
  • Regarding your comment in para 4, I tried setting the V6 II to AUTO to check whether it could detect my Nikon D3s as the camera system and it could not!
    In this case, you cannot expect HSS or PowerSync to work. Normal triggering with shutter speeds that do not exceed the sync-speed should still work, but for higher shutter speeds, the V6II needs to be able to recognise the camera during the auto detection phase.

    Hopefully Cactus can advise whether they ever tested the D3s with the V6II.

    Have you tried moving the V6II a bit in the hot-shoe? Perhaps try pulling it back half a millimetre or so after inserting it. I know that the D750 has a non-standard hot-shoe that needed a bit of adjustment tricks for the V6 to work. While I haven't heard anything like this regarding the D3s, it is possible that a slight adjustment of how the V6II is sitting on the hot-shoe may help. 

  • As an alternate idea I tried it out with my D300s and that worked OK and then placing it back on the D3s now seems fine. Perhaps it was a positional thing  
  • Glad to hear it worked.
    Please let us know if you require further assistance on your D3s.
    Thank you!
    Antonio Lao
    Brand Manager

    To help us better help you, always state the exact firmware version installed on your Cactus device(s), such as: "1.1.013", "NIK.A.001", "v.103", or "A06".

    TTL or HSS not working on Cactus V6 II and V6 IIs? Be sure to check hot shoe connectivity by doing the <CAMERA INFO> check.

    Feel free to suggest an improvement or share product ideas. Contact us directly at  At Cactus, we listen. 
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