Sea n Sea 110a and Inon Z240-III

[Ardy]

Hi all

Just read Scott Gietler's great article on flashes and it brought up a couple of concerns.

I have an Olympus E-520 with a 50mm macro lens used for fish and macro. I have a SnS 110a and it has been good so far but I found a bargain Z240-III and grabbed it thus retiring my manual slave SnS and moving to TTL (first time in a long time).

I have been out of the water for 10 months with a major back operation and am off to Bali to dive Tulamben in September. Have not used the Inon 240 underwater yet and wondered what the best set up of these strobes would be? I plan to use them both in TTL if possible with the Inon Z240 as master.

I have tested them out of the water and it seems to work OK with both set in TTL but would like to get some advise rather than fart around in Bali when I only have 3 days diving.

regards

 

[bvanant]

How many fiber optic ports does your housing have? If it has two then just use two fiber optic cables. I haven't tried the permutations to see how they do with one as a slave.
Bill

 

[Ardy]

Hi Bill - my housing has two optical ports and I have set them up to work off separate cables. I have tested it above water extensively but just concerned that it won't work underwater for some reason.

Seems strange to me that two flashes both set to TTL and firing off the same camera don't over expose the shots. They must allow for the others flash somehow?

 

[bvanant]

In STTL mode the camera sends out a pre-flash. In your case the pre-flash tells BOTH strobes to send out their pre-flash which means that the camera then samples the scene with BOTH strobes sending out the preflash. The camera then decides how much flash is necessary and sends out the main flash. In this case then BOTH strobes see the same signal (which is half as big as it would be if you only had one flash) and then both strobes fire.

Bill

 

[Ardy]

That is very neat Bill. I wonder how they achieved that but this technical stuff doesn't grab me as much as it used to do.

thanks a lot.