OM-D EM10 flash sync speed (optical cable)

[ProfF]

Hi,

I had the chance to try out my new EM10 in the water. I have NA-EM10 housing and two YS-D1 connected with optical cables. AFAIK the fasted sync speed is 1/250th. However, at times I would get images where only the bottom of the picture was exposed --- as though the curtain and the flash were out of sync. I attached two pictures taken one after the other, the first was properly exposed (terrible backscatter etc) and the second not. As far as I remember I repositioned the strobes, but not much else. This happened to me again several times.

I was shooting in Manual mode, fill-flash, strobes set to TTL.

Any ideas what can be the cause of this problem?

Thanks!

Nir

 

[bvanant]

AFAIK, the sync speed for external strobes is 1/200th not 1/250. You can easily test this on your kitchen table. You will be far better off in the future shooting those strobes in manual.
Bill

 

[ProfF]

AFAIK, the sync speed for external strobes is 1/200th not 1/250. You can easily test this on your kitchen table. You will be far better off in the future shooting those strobes in manual.

Bill,

The advertised sync speed on the camera is 1/250 (and faster for olympus flashes). I haven't checked if the strobes have maximal speed. I did do dry tests which were successful (as well as some of the underwater photos).

I go back and forth between manual and TTL strobe setting. Since this was first set of dives with a new camera I stayed with TTL for now.

Nir

 

[PHIL RUDIN]

With optical cables firing your YS-D1 strobes the maximum sync speed is the 1/250th with the built-in strobe that is firing the external strobes. If hard-wired the sync speed would be 1/200th. You should be getting consistent exposures the way you have the camera setup and even if you the strobe was out of sync with the shutter curtain it would not be this extreme at 1/250th. If the pop-up flash is in sync with the shutter every time the issue is with the YS-D1 strobes not the camera. Try shooting at 1/250th with the built-in flash and a lens that won't block the flash output and see if it is consistent.

 

[amnong]

Are you using fill in flash or flash intensity control (to save battery). With Inon strobes, when using flash intensity contro,l I have to disable the ACC (pre flash, advance cancel circuit) in order to trigger the strobe properly (while in all manual mode). 1/320 with the E-M1 and no issue so far. I suggest to try all the manual and then narrow down until you get to TTL. It may has to do with the pre-flash on either the camera or the strobe.