Strobe not synching

[Rainer]

Recently acquired a pair of Inon Z240s for our Nikon D7000 (Aquatica housing). The seller included a pair of Toslink cables (with ends to mate to the strobes). I hooked everything together and took a test photo into a mirror. Only the right strobe is showing as firing in the photograph, even though both strobes clearly do fire. The left strobe is obviously firing too early or too late (I'm assuming probably the latter). I've jiggled the connectors, but can't seem to find an obvious solution.

Any suggestions greatly appreciated. Would love to get this fixed today if at all possible, as we were hoping to dive tomorrow.

Thanks!

---------- Post Merged at 06:00 PM ---------- Previous Post was at 03:25 PM ----------

Here's what I've tried:

Shooting TTL (both strobes), focus assist lights off, both strobes fire, but only the right strobe syncs.
Shooting TTL with only the left strobe on, it fires, but it does not sync.
Shooting manual on the left strobe (and with either the left strobe on or off in TTL), both fire *and* both sync.

So what could be accounting for the left strobe not synching in TTL?

As far as the ACC circuit (which I don't really understand), both are in the "up" (non-depressed) position. Is that correct?

Thanks.

 

[Nemrod]

It is possible the ACC circuit is faulty on one of the strobes. With your D7000 set in manual, just to make it easy and after consulting your camera manual to make sure there are no pre-flashes which being a dSLR, should not be, set both strobes to ACC OFF. Make sure the strobes are in the off position when you cycle the switch. Set strobes to Manual. Test fire again.

I assume the strobes are linked individually to the camera and not to each other and that you are using a sync cable and not optical cable.

N

 

[Rainer]

These *are* fiber optic cables (one for each strobe). The DSLR is set to TTL, so it will preflash. Is ACC "off" with the dial pushed in or left out? Which setting do I actually want? The ACC description in the manual is as clear as mud.

Thanks!

 

[Nemrod]

These *are* fiber optic cables (one for each strobe). The DSLR is set to TTL, so it will preflash. Is ACC "off" with the dial pushed in or left out? Which setting do I actually want? The ACC description in the manual is as clear as mud.

Thanks!

OK, if the dSLR is emitting a pre-flash as you say in TTL, that is why I asked for you to set it to Manual and ensure that the camera flash is set to Manual--no TTL-- and then test the strobes.

I am not 100% on the Z240 like I am on the S/D series, I think that IN (Normal) is ACC on which is what you want when the camera is set to emit a pre-flash. This is easy though to test in the mirror as you have done. Try both ACC switch positions. I believe that even on the Z240 you are NOT supposed to actuate the switch while the strobe is ON.

ACC on for pre-flash sync.

ACC off for no pre-flash sync.

N

 

[Rainer]

Both strobes work fine in manual (I noted this above). One is not working when the camera and strobe are set to (S)TTL.

Is ACC "on" with the dial "in" or "out"? I've tried both and still get the problem.

Any thoughts on what could be the issue?

Thanks for taking the time to help!

---------- Post Merged at 02:58 PM ---------- Previous Post was at 02:50 PM ----------

-Strobes set to M, camera set to TTL: both strobes sync
-Strobes set to STTL, camera set to TTL: only the right strobe syncs (i.e. "the problem"), but both fire
-Strobes set to M, camera set to M flash (1/10 power or higher): both strobes sync
-Strobes set to M, camera set to M flash (less than 1/10 power): only the right strobe fires (the left doesn't even fire, nevermind sync)
-Strobes set to STTL, camera set to M flash (1/64 power or higher): both strobes sync (image is blown out)
-Strobes set to STTL, camera set to M flash (less than 1/64 power): only the right strobe fires (the left doesn't even fire, nevermind sync)

 

[bvanant]

Are you sure that they sync when the camera is on TTL and the strobes are manual. that seems wrong to me. You mentioned that these are Toslink cables and the key piece of data is that at less than 1/10 power the "bad" strobe doesn't fire. Can you get hold of an Inon or Nauticam or S&S fiber? My bet is that the cables are just marginal. With name brand cables my Z240 strobe fine at 1/128 power.
Seems like if it is not the cable it is the strobe sensor.
If you care to bring them up to Valencia I think we can probably sort it all out or we can meet somewhere mutually convenient if that works.
Bill

 

[Nemrod]

Both strobes work fine in manual (I noted this above). One is not working when the camera and strobe are set to (S)TTL.

Is ACC "on" with the dial "in" or "out"? I've tried both and still get the problem.

Any thoughts on what could be the issue?

Thanks for taking the time to help!

---------- Post Merged at 02:58 PM ---------- Previous Post was at 02:50 PM ----------

-Strobes set to M, camera set to TTL: both strobes sync
-Strobes set to STTL, camera set to TTL: only the right strobe syncs (i.e. "the problem"), but both fire
-Strobes set to M, camera set to M flash (1/10 power or higher): both strobes sync
-Strobes set to M, camera set to M flash (less than 1/10 power): only the right strobe fires (the left doesn't even fire, nevermind sync)
-Strobes set to STTL, camera set to M flash (1/64 power or higher): both strobes sync (image is blown out)
-Strobes set to STTL, camera set to M flash (less than 1/64 power): only the right strobe fires (the left doesn't even fire, nevermind sync)

I am fairly sure that the ACC circuit is ON when the switch is the "Normal" position which is IN.

However, Bill may be on to something and had a good thought.

Since these are used strobes, I have encountered two Inon strobes where the ACC circuit was faulty, one here in scubaboard and the other an acquaintance I dove with on a trip.

I assume, maybe you said, that you swapped the cables?

The older Inon strobe light sensors (which sense IR) are not as sensitive as the newer versions, perhaps Bill is correct in that one of the cables is a poor conductor.

N