Sea & Sea pre-flash emulation/ignore in DS-TTL

[DazedAndConfuzed]

I posted in strobe forums and got no response, so I will try here.

I noticed many people complain about Sea&Sea YS-01 or YS-110a compatibility issues with their cameras in DS-TTL. Is it the fact multiple pre-flashes are used to meter the amount of light needed for the final flash?

I have a camera with 1 pre-flash and it seems to work properly in TTL mode on my topside test. I also tried it with my camera set to red-eye reduction, thus giving many pre-flashes. I see the strobe perform only one pre-flash, ignoring the rest of the red-eye reduction flashes, then lights up at the end on the main flash, and the exposure comes out properly. Not sure how it knows all the red-eye reduction flashes are not real-flashes and only do the final flash. If it knows all that, you think it knows about multiple pre-flashes, or maybe it always ignores weak flashes after the 1st flash?

 

[SEA&SEA]

There are several factors involved with the DS-TTL functionality and a few are the number of preflashes, sequence and time/delay, and intensity. The YS-110a and YS-01 firmware are programmed to detect the preflashe(s) and read the main flash output properly. Reliable DS-TTL reading and output also requires proper light from the main flash getting to and being received by the strobe sensor via fiber optic cable. So, if the cable is not positioned properly or has an issue, that can effect performance as well. With a myriad of cameras on the market and hundreds developed each year, it is not possible to accomodate all. Possibly in the future, there may be firmware updates available for strobes and YS Converters to update compatability, however, not at this time.

 

[DazedAndConfuzed]

I thought the strobe only has trigger the flash the instant it senses it in its optical sensor port and stop it when the light stops coming to the port. It would not care if there are multiple pre-flash, strong and weak combination pre-flashes. It will just mimic them, just in a more powerful manner.

Also, wonder why the red-eye pre-flash got completely ignored. Is it because it was going on and off too fast?