I’m glad you found this helpfull

Flash duration changes with power setting on the AD600. If you look on the screen, it will show you the flash duration for a given power setting

High speed sync is for controlling ambient light, not freezing fast movement, so the person that gave you that advice either didn't know what you were trying to do, or just didn't understand how the flash works. The only way to freeze fast movement is with a fast flash duration. What model is your Elinchrom light?

First of all, don’t use HSS to freeze water droplets, it won’t work. You need to set your V1n to a very low power to get a short flash duration and get your camera shutter below sync speed so you’re not using HSS. HSS is very demanding on your flash and batteries. If you se it too high, and try to take multiple photos quickly, the flash won’t have time to recycle. There are no flashes that can keep up with continuous flashing at 1/1000 If you want to freeze water drops, set your camera to 1/160 shutter, your flash low, and keep ambient light very low so it doesn’t affect your exposure. HSS if for shooting outdoors in full sun, not to freeze action.

@@MartyKPhotography I freeze water with HSS at 1/1600 with no problem

High Speed Sync or HSS is really for fill flash in bright sunlight when shooting above the max X or sync speed. That's the primary use. Any freezing action is just incidental. Flash duration is the real hero when comes to freezing action. HSS at 1/1600s or even 1/8000s is indeed very fast but no where as fast as 1/19000s that's flash duration that really freezes water droplets.

There are many reasons that could be happening. Are you able to share your image with me?

Take a picture without the flash, set shutter at max sync speed, 1/200s in your case, set the aperture so you get a black frame, for example f/8 depending on the ambient. Now turn flash on so you can illuminate the subject at that f/stop. If you are shooting outdoor and can't get a black frame w/out going higher than the max sync speed then you need to use high speed sync or hypersync or some ND filter to manage the exposure.. If your subject moves or the shutter speed is low enough you can get ghosting which may or may not be a desired effects. For action shots a trailing light (rear sync, flash fires at the end of the exposure) maybe a desired effect.

From the official D2 spec sheet

MartyK Photography thanks, I missed this in the spec sheet last time I looked. The Godox QT600II seems to have a significantly shorter T0.1 when compared to the D2

Oh really? What’s the T1 of the qt600?

MartyK Photography 220V version (for countries like Australia) 1/28,884. 110V version (for countries like USA) 1/19,606. Their 400Ws strobe goes down to 1/35,086 for the 220V version.