double sb-800 usage

I'm trying to use a pair of sealux housed sb-800 flashes with a Sea & Sea NX100 housed Nikon F100. The camera housing has two strobe connectors. When I try to connect two sb-800 flashes to the camera over these two connections and set each flash to TTL mode, I receive an error on the camera. I think this is because only one sb 800 wants to communicate with the camera simultaneously in TTL mode. After my investigations I have found out below solutions. Any suggestions welcome.

1. Each connector has 5 pins. One strobe should be connected to the housing with all 5 connections. And the other strobe has to be connected over only 3 connections. This solution seems the to be the easisest one if it works.

2. Only one strobe may be connected to the camera and a ttl cord connection may be set up between two sb 800 flashes, which will require some modifications on flash housings and is not so easy.

3. Trying to run the system in wireless flash mode, which I believe wouldn't work cause the relevant sensor might not seize the light since the flash is in an housing.

Any experience or comment welcome. Thanks in advance,

Murathan.

Hello,

According to what I've read, when the F100 is placed in Matrix mode, it performs 3D multi-sensor balanced fill flash. This is a D-TTL system, and D-TTL is only capable of controlling one flash via the cord.

Second - you could have a problem with both flashes sending the ready signal to the camera. That is why most dual sync cords have a primary and a secondary connection - only one sends the ready signal. It sounds like you understand that part.

You may want to borrow a Nikon dual cord and try that with your system, as opposed to two single cords - just to see what happens.

In any case, it's not going to be easy - it's going to be complicated. Why did you choose such a complicated setup, instead of going with dual TTL underwater strobes?

Cheers

James

Hi James,

Thanks for your message. I actually wanted to invest on flash equipment which I could use newer nikon bodies. That is actually the reason I preferred sb-800 flashes.

So, I'll try to avoid the second flash to send the Ready signal by cutting the two connections of the second flash. I hope it will work.

This configuration (both connected over 5 pins) still allows me to use one of the flashes in TTL mode and the other in manual mode, but this is something I'm not happy with.

Murathan.

Hang on! With an F100, you should be able to use two cord-connected flashes in TTL mode.

One flash has trigger, ground, TTL-quench, Ready-light, and #5 (can't remember this one) connected and the other one has trigger, ground, and TTL connected. The SB800's should default (or be set) to "good old" TTL.

That's why I say you should get a Nikon dual cord SC-100 - it should work and you won't have to cut anything.

Cheers

James

Hold your horses James... though you did catch yourself at the end.

SB800's do plain old nikon TTL protocol when used with a compatible film camera

Only one flash can be allowed to send "ready" info to the camera, as you say.

Other flash should have trigger, ground and QUENCH.

I've used dual nikon TTL-protocol strobes with the Sea and Sea f100 housing, I used the Ikelite nikonos->dual ike y cord (as you are suggesting above).

Hi Craig,

Thanks for your message. Do you know how are the trigger and quench pins located on the flash connector?

Cheers,

Murathan.

Hi,

I think I've found it: http://www.camerasunderwater.co.uk/info/te...ges/nikttl.html

Seems that ttl with double sb800 works now.

Thanks,

Murathan.