HI. Sorry,, the last month was extremly busy.
So this black line a the top is sync problem. I never seen same problem with popular strobes, but the SUPE-D was never tested by me. The MF-2 works perfect.
In the past few weeks, I have been testing a few new flashes on the market, and I noticed that manufacturers do not fully test their products. The sync of the Sony trigger flash comes from the camera and is transmitted to the trigger LEDs within 1-2 microseconds, which should not cause such a problem. So, I don't think this is a trigger issue. However, I am happy to take some shots with an oscilloscope and a light transducer to measure the time between the trigger signal and the flash of any underwater flash. ๐
Just for sample. This is a preflash power from Z330.