Flash sync problems

[LeeCat]

I'm using Nikon D800 in Nauticam housing, 2x YS-D1 strobes with optical sync. On some images, about 20%, I have strongly underexposed bottom part of the frame - about 15-20% of the vertical size. The same effect randomly appears at different shutter speeds (1/200 to 1/320), with normal and rear-curtain sync. I don't see any regularity in the event and I can't reproduce it on land photos with built-in flash.

I'll be very much appreciated for any ideas.

 

[bvanant]

This is quite strange, unless you are shooting a pre-flash. What mode is the camera in and what mode is the strobe in? Certainly 1/320 is too fast, that sync is only possible I think with Nikon Speedlight, but 1/200 should be fine.

Bill

 

[jimbeeler]

I'm using Nikon D800 in Nauticam housing, 2x YS-D1 strobes with optical sync. On some images, about 20%, I have strongly underexposed bottom part of the frame - about 15-20% of the vertical size. The same effect randomly appears at different shutter speeds (1/200 to 1/320), with normal and rear-curtain sync. I don't see any regularity in the event and I can't reproduce it on land photos with built-in flash.

I'll be very much appreciated for any ideas.

Did you check (and slow down) the Flash Sync Speed? I never heard if this was solved from the message you posted in the Nikon forum.

Jim

 

[LeeCat]

Did you check (and slow down) the Flash Sync Speed? I never heard if this was solved from the message you posted in the Nikon forum.

Jim

I didn't do UW photo since my last trip and I can't provide the results. I'll try it on the 1st possible occasion. Thanks for response.

---------- Post added May 23rd, 2014 at 02:10 PM ----------

This is quite strange, unless you are shooting a pre-flash. What mode is the camera in and what mode is the strobe in? Certainly 1/320 is too fast, that sync is only possible I think with Nikon Speedlight, but 1/200 should be fine.

Bill

I guess I'm using pre-flash: the camera flash and external flashes are in TTL mode. And, if I'm not mistaken, 1/320 is supported with camera flash as well. The camera flash does not support "high speed sync" - faster 1/320. The mode supported with Speedlight only (and not with all models )