HSS (high speed synchronization) is a neat thing when you want to use small apertures in combination with flash photography.
Cactus V6II enables you to fire flashes as short as 1/8000s. That’s possible by forcing the Cactus V6II to HSS mode.
Unfortunately at the time of writing (2016-12-31) you have to flash a beta firmware on your Cactus V6II if you are using the XPro2 with a firmware >= 2.0. Otherwise only sync times up to 1/250s will work. If you try to do shorter syncs you’ll get the well known non-exposed black bars in your pictures meaning HSS failed 🙂 Just follow this forum post to get it working properly (Windows and MacOS) The next stable Cactus firmware should be flashable the official way with their updater. Stay tuned!
The MacOS updater did contain an old version as of 2016/12/31. Just use the “check update” button in the updater app and you’ll be good to go. Alternatively you could use the Windows updater app, as the newest firmware is already embedded there!
The updater apps can be downloaded here.
I had a lot of ghost triggers when using the Cactus V6II with three Cactus RF60 wireless flashes. They fired without the trigger being pulled. I’ve tried to switch distance mode between SHORT/LONG, changed channels, but it didn’t help. Couldn’t get rid of the ghost triggers.