Nikon SB-910 Not Delivering Full Power

Hi
I have recently bought the V6 to use with my Nikon SB-910 along with a couple of RF60's. I have latest firmware loaded on V6 and RF60's. I noticed that on 1/1 power the RF60's were putting out a lot more power than the SB-910, I confirmed this by measuring with a flashmeter.
I then switched the exposure compensation on the Sb-910 to +3 stops and then it delivered full power. It seems that if you leave the SB-910 with 0 exposure compensation it drops the max output by 3 stops. Surely the V6 should be able to control the full range of the SB-910? Also, if I have +3 stops dialled in, I am guessing that I wont get a true 1/128 from the Nikon, maybe 1/32 actual power. Any comments?

Thanks
Rich

Comments

  • Also forgot to mention, that no matter what zoom setting the SB-910 was at before activating the V6 it sets the zoom to 200mm.

    Thanks
    Rich
  • Hello @Rich_LT

    I have forwarded your case to our R&D team and will get back to you as soon as we can.

    Yes, auto zooming to 200mm happens on Nikon flash models.
    Press and Hold the MENU button for 2-3 seconds, the flash will be unlocked, and you can manually adjust the zoom range of the SB-910.

    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", "FUJ.1.002", "v.103".

    For the time being, Cactus V6 (MK1) running on firmware version 2.1.001 can be triggered by a V6 II (MK2) running on Multi-brand HSS firmware (e.g. 1.1.013) and not by X-TTL firmware versions: PEN.A.001 and OLY.A.001.  No schedule has been released yet. 

    Cactus RF60X / RF60 Firmware versions A01 and A02 currently ONLY works with PEN.A.001 and OLY.A.001.  Other "A" version of X-TTL firmware will be released soon. For both Multi-brand HSS and X-TTL firmware versions (FUJ, SIG, SON), install firmware version 103 / 205 on your RF60X / RF60.

    Cactus RF60 is now an off-camera TTL flash with firmware version 205 or later!

    Metz M400 (for Fujifilm) is now supported on the Cactus V6 II (HSS and TTL).

    Nikon D750 users please read this thread: 

    Fujifilm EF-X500 users please read this thread:

    Feel free to suggest an improvement or share product ideas. Contact us directly at info@cactus-image.com.  At Cactus, we listen. 
  • Hi @Rich_LT, BTW, why did you compared the power outputs of two different flash models? Because the SB-910 is indeed a tad more powerful than the RF60.

    I did two tests for the SB-910, first round I set the flash profile for NIkon, SB-910 in TTL mode, and remotely contorlling its power and firing it from another V6. Second round, I set the flash to M mode, selected Manual Flash on the V6 RX unit and simply triggering it from another V6.

    The reading on my Sekonic light meter is 22.8 and 22.3 respectively - the power was greater when the flash was set to TTL mode than was it in ful manual mode. But there could be minor placement differences of the flash that changes the angle and distance from the light meter that may not fully reflect the actual light output. However the power levels are very close.

    Please let us if you have any further observations.

    Thanks!
    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", "FUJ.1.002", "v.103".

    For the time being, Cactus V6 (MK1) running on firmware version 2.1.001 can be triggered by a V6 II (MK2) running on Multi-brand HSS firmware (e.g. 1.1.013) and not by X-TTL firmware versions: PEN.A.001 and OLY.A.001.  No schedule has been released yet. 

    Cactus RF60X / RF60 Firmware versions A01 and A02 currently ONLY works with PEN.A.001 and OLY.A.001.  Other "A" version of X-TTL firmware will be released soon. For both Multi-brand HSS and X-TTL firmware versions (FUJ, SIG, SON), install firmware version 103 / 205 on your RF60X / RF60.

    Cactus RF60 is now an off-camera TTL flash with firmware version 205 or later!

    Metz M400 (for Fujifilm) is now supported on the Cactus V6 II (HSS and TTL).

    Nikon D750 users please read this thread: 

    Fujifilm EF-X500 users please read this thread:

    Feel free to suggest an improvement or share product ideas. Contact us directly at info@cactus-image.com.  At Cactus, we listen. 
  • Hi Antonio
    Many thanks for getting back to me.

    "Hi @Rich_LT,
    BTW, why did you compared the power outputs of two different flash
    models? Because the SB-910 is indeed a tad more powerful than the RF60."

    I didn't set out with the intention of comparing 2 flash models. I noted when the RF60 was at 1/1 power you could hear the capacitor fully discharge with a ping. I noticed that my SB-910 was not emitting that ping which got me thinking its not giving out full power on 1/1.

    I carried out the test again tonight, sekonic meter on stand 2.5m from flash. ISO 100, flash zoom 24mm. With Nikon flash set to TTL mode, V6 set to SB-910 and 0EV flash compensation set on SB-910 I get f 11.2. V6 removed SB-910 in manual mode 1/1 power fired using test button I get f13.2.
    Then put V6 into manual mode and got F13. Then gave the SB-910 +3EV in TTL mode again using V6 to trigger and got f 13. Reduced flash compensation to 0 EV and it dropped back to around f 11. So it seems that I have to dial in +3 EV to get the SB-910 to give a full flash.
     

    Thanks
    Rich
  • edited January 2016 PM
    Hi Rich,

    I understand your problem -- ideally the SB-910 should be emitting full power when fired at 1/1 through a V6 without requiring an addition +3EV compensation -- but I'd like to point out that the difference between f/11.2 and f/13.2 is just slightly less than half a stop.

    In other words, its not a huge difference (certainly not the "+3 EV" one might expect).

    From what I understand, it can be normal for a digital TTL flash to put out less light at a nominal "full power" in TTL mode, compared to the absolute full power that can be unleashed using manual mode.

    Whether this behaviour is intended to have a bit of headroom for an additional positive exposure compensation (to make such a flash actually brighter than other TTL flashes at "full" TTL power), I'm not sure, but I'm pretty sure that I've come across this phenomenon.

    I guess a V6 could compensate for this phenomenon by instructing the flash to fire at "1/1 ++", but I can't really say whether that is actually within the capabilities of Cactus to achieve that.

    Choosing this route, however, may make it harder to use an SB-910 on a V6 (driven manually) in combination with an SB-910 on-camera (in TTL mode). These two flashes would probably not agree on what "full power" means, as I'd expect the on-camera SB-910 to not really put out maximum power. If you have a Nikon camera, you may be able to check what the result of "full" TTL power (with 0 EV compensation) of an on-camera, TTL-driven, SB910 is.

  • Thanks for your reply. I will carry out that test. Stupid question, but when the flash is in ttl mode being triggered by V6, does it send out a pre-flash? I know it does not use this but it would account for a slight loss in power.

    Thanks
    Rich
  • Rich_LT said:

    Thanks for your reply. I will carry out that test. Stupid question, but when the flash is in ttl mode being triggered by V6, does it send out a pre-flash? I know it does not use this but it would account for a slight loss in power.

    No there is not pre-flash.

    Interestingly, what Class A described has been the standard phenomenon - TTL flash never really fires full power, at least not as "full" as M mode. but in my own tests here in the studio, in two different testing scenarios (different zooms and distance from light meter), the full power of the SB-910 was measured lower in M mode, though by a very small margin: 22.8 vs 22.3. I'd say it is pretty close to the real full power...
    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", "FUJ.1.002", "v.103".

    For the time being, Cactus V6 (MK1) running on firmware version 2.1.001 can be triggered by a V6 II (MK2) running on Multi-brand HSS firmware (e.g. 1.1.013) and not by X-TTL firmware versions: PEN.A.001 and OLY.A.001.  No schedule has been released yet. 

    Cactus RF60X / RF60 Firmware versions A01 and A02 currently ONLY works with PEN.A.001 and OLY.A.001.  Other "A" version of X-TTL firmware will be released soon. For both Multi-brand HSS and X-TTL firmware versions (FUJ, SIG, SON), install firmware version 103 / 205 on your RF60X / RF60.

    Cactus RF60 is now an off-camera TTL flash with firmware version 205 or later!

    Metz M400 (for Fujifilm) is now supported on the Cactus V6 II (HSS and TTL).

    Nikon D750 users please read this thread: 

    Fujifilm EF-X500 users please read this thread:

    Feel free to suggest an improvement or share product ideas. Contact us directly at info@cactus-image.com.  At Cactus, we listen. 
  • I did one final test to see if it was clipping at the 1/128th power setting. Set the flash to flashmeter distance at 1m, ISO 800, 24mm zoom. With 0EV set on flash I get f36, then using -3EV on flash I get f23. This would only be important I guess if you are trying to achieve a very brief flash duration, say for freezing motion as you could change your flash/subject distance if it was too bright. I think the range is clipped top and bottom end by just over a stop when flash is set to TTL, which is no big deal as long as you are aware of it and you make the necessary +/- EV settings of flash if required.

    Thanks
    Rich
  • edited January 2016 PM
    @Rich: I agree that getting the lowest possible power can be important to get the briefest possible flash duration.

    Note that you should be able to engage "LO POWER" on the V6 which should give you a setting below 1/128 (that is not quite 1/256 from my measurements). It should still reduce the "clipping" at the bottom end to less than 1 stop.

    Regarding the clipping at the top, according to your measurements, it is just a little bit less than half a stop.

    Since your results and Antonio's results are conflicting it seems impossible to conclude whether TTL + EV enables a range that is wider than the range accessible through manual levels or not.

    I think it would be important for the V6 to recreate the manual levels of the flash, as opposed to providing access to a potentially larger range of levels (made available through additional EV compensation on the flash).


  • My only comment on this is I don't believe you even need to measure it, listen to the sound the flash makes. At 1/1 power in manual mode not using the v6 the flash pings. Then attach a v6 flash in TTL mode 1/1 power and it does not. Then add +3EV and it pings again giving out full power. It's definitely clipping both ends. Thinking about it this must happen with the flash when attached to the camera in TTL mode, that's why we still have +/-3EV to play with. It must also be clipped so the V6 is faithfully reproducing what the sb-910 does in TTL mode. What we really want is the V6 to produce the full MANUAL range of the sb-910 not the full TTL range.

    Thanks
    Rich
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