Inon D2000S and Ikelite DS51

I switched over to Inon D2000s Type 4 with my Canon S90 and am pretty happy with it. I have a Inon 100 WAL type 2. Would like to do some CFWA (like I used to with my Nikon 16mm). Can I use the Ikelite with Inon assuming I buy their Fiber Optic Adaptor #4401. I realize that the DS51 would be on manual so would use it for background lighting. Adjustment is by knob on Ike or by Inon?

Sound right to those in the pool?

I believe with the Ike optical trigger, you get manual triggering only. So you would adjust the Ike lighting intensity with the knob on the back of the DS51. Adjusting the Inons (or the camera flash) wouldn't alter its output in any way.

i've used a DS51 with inon D2000 before.

THe DS51 was connected to the camera housing using the eletrical sync cord so I get TTL. The D2000 was on the other strobe arm, and i left the fibre-optic sensor open and pointed towards the DS51. The D2000 was on STTL mode.

With this arrangement, I get TTL strobe control from both strobes, and no extra cords running between the DS51 and D2000

maybe I FAILED to say that I am using a Fisheye Fix housing so there is NO electrical connection available. I was thinking of putting DS-51 on manual, adjust by the knob, and using f/o cable from Ike adaptor to the housing?

I use the Inon's External Auto setting pretty successfully.

I don't know if you're triggering the Inon now with fiberoptic or just 'wirelessly' (the photodetector sees the camera's flash). But regardless, the issue is going to be that the Ike doesn't have any sort of 'external auto' mode but triggering only with their fiberoptic adaptor. All control is from the dial on the back.

So if the Inon is 'wireless', once you add the Ikelite, more than likely it's the Ikelite that gets mimicked by the Inon. The Ike is going to be the brighter source so when it flashes it triggers the Inon, and when it quenches it triggers the Inon to quench. So in that case adjusting the dial on the Ike is adjusting 'both' of them sort of. I'm guessing you'd just block the on-camera flash to only what makes it thru the F.O. to make sure. (I'm probably mixing up S-TTL optical with external auto modes...I really have a hard time understanding the Inon manual I downloaded).

If the Inon is on fiberoptic to the on-camera flash as well (e.g. the photodetector doesn't really "see" the Ikelite flashing), you might get a confused result: the Inon might successfully S-TTL trigger and quench based on the on-camera flash, while the Ike only triggers but can't quench in response to the on-camera flash. Adjusting the dial on the Ikelite is only adjusting the Ikelite in this case. So while one is trying to do TTL communication with the camera, the quench command isn't being obeyed by both, and I'm guessing this might be more frustrating than the case above, where you've lost all TTL and are essentially shooting manual, but at least one adjustment is in effect adjusting both strobes.

Disclaimer: I don't and never have owned any Inons (yet). Been researching them. One friend tells me he sets one to external auto and the other adjusts manually, triggered by electrical cable to the on-camera strobe hotshoe (he's on an Ikelite housing, but with 2 Inon strobes, so the on-camera flash is down and doesn't flash, the included electronics see the hotshoe pulse but can only offer manual triggering to non-Ikelite strobes). So he can only shoot with manual strobe control, but one knob adjusts both strobes in most cases. Sort of sounds like what you'd be forced into, but with the Ike F.O. connection replacing the electrical sync manual trigger.

I do use the f/o cable to the S90, and I use EA mode which is in essence an u/w flash meter. It will quench the Inon but not sure how the Ike strobe will affect that?

I am assuming that if I dial DOWN the Ike, then I will get a primary and slave effect with the Inon metering? BTW S90 flash fires at reduced level to trigger.

I am used to adjusting knob and shooting in manual, I shot Ike strobes for 20 years~