Hello
I use a UWTechnics flash trigger with a sony A7RIII and Nauticam housing
When I want to use my strobes to take slow shutter speed photos, I have a problem
I put my Inon Z330 strobes in Manual mode, rear curtain flash on the Sony A7RIII and below a speed of 1/15s it does not flash correctly
I explain:
For speeds of 1/15s and more, no problem, a pre-flash fires, then 1/15s  later the real flash appears on the rear curtain
However, from a speed of 1/13s or less, the flash on the rear curtain is very weak (like a second pre-flash) and does not sufficiently illuminate the scene to be photographed.

On front curtain it works well for any shutter speed

This problem appears only on rear curtain with speed under 1/13s
Do you have an idea to solve this problem?
Thanks you

Edited May 30, 20241 yr by JB_Cazajous

Hi JB

did you set your Z330 to ignore the preflash ?
small button on right.

Push or pull, I do not remember...

Edited May 31, 20241 yr by FrancoisC

Hello Francois

Actually the function of this button is not to ignore the preflash, but to let my Z330 understand if my camera is going to send a preflash to it.
If I activate it (button pressed) the Z330 will consider the preflash of my camera as the main flash
A black image follows.

I would think the problem lies within the camera/UWT trigger combination.  When in manual the INON strobe just fires when it receives a light pulse.  You might be best to message Pavel if he doesn't chime in.

After many tests, I finally found the solution!!! 😁

 

On the UWT trigger there is a small dial which allows you to configure the trigger according to the strobe you own
This one was on position 6 which corresponds to the Inon Z330 strobe
This allows you to use the Z330 in s-TTL mode, but it creates a pre flash

Switching this dial to position 0 completely disables TTL mode, but it also disables preflash

All I had to do then was press the preflash button on my Z330 strobes

No more rear-curtain flash sync problems below 1/15s

Edited June 2, 20241 yr by JB_Cazajous

37 minutes ago, JB_Cazajous said:

After many tests, I finally found the solution!!! 😁

 

On the UWT trigger there is a small dial which allows you to configure the trigger according to the flash you own
This one was on position 6 which corresponds to the Inon Z330 strobe
This allows you to use the Z330 in s-TTL mode, but it creates a pre flash

Switching this dial to position 0 completely disables TTL mode, but it also disables preflash

All I had to do then was press the preflash button on my Z330 strobes

No more rear-curtain flash sync problems below 1/15s

 

Excellent news!  I have the same setup. Currently I have the UWT trigger set at 0 and use the Z-330s in manual.  If I want to change to TTL, this will be very useful information.  Thanks again!