I bought 2 v6ii recently, just to play with wireless HSS.
loaded with pentax firmware with the offical software,
Note, check the compatible list, my previous K-01 camera is not online the list, and any speed higher than 1/180, the trigger will trigger but the flash and shutter is not in sync, no matter what setting you use, since K-01 is not on the compatible list.
luckily, K30 is on the compatible list
1. one v6ii on K30, one pentax AF540FGZ on the other v6ii,
remote TTL and HSS and remote power control all works automatically.
2. Godox FT-16 single pin trigger on top of one v6ii (as nikon flash mode as for translation in sync), which on top of K30, (yes only one v6ii needed to force hotshoe to talk to non pentax flash or trigger), godox receveir usb on Godox AD360 mark I,
use FT-60 to talk within godox flash stuff, like power control
pentax K30 will shutter sync with AD360 flash, if you want HSS, you just need to set HSS on on AD360.
which great for outdoor shoots with this powerful flash.
3. AD360 mark I directly on top of v6ii, which on top of K-30, (3 stack together) (v6ii set to nikon flash for translation in sync)
it works as well like normal and HSS, but the flash is so huge, and stacking like that is too high
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4. of course, you can use other v6ii to connect the AF540FGZ, (no time to try yet)
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but you can HSS with any flash with light trigger built-in with any mordern flash (S2 mode works for me), but you need to set those flash like YN560s to full power to able to cover the shutter duration.
as long as you have a master flash that can get HSS signal from camera body, like AF540FGZ or the v6ii "translation" trigger.
note, the on-board tiny pentax camera flash doesn't support HSS, can't go pass 1/180 shutter speed, at least for K-30 case.
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note.
the new AD360II support canon or nikon ttl, so you can use another v6ii to talk to it directly by mounting without godox trigger.
however, if you got a lot of godox morden flash, then get the godox newer X series trigger is better option, since those new godox flash got godox receiver built-in. like AD360ii, AD600
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extra info,
I used to use YN560 TX trigger and those YN560 iii and iv system, but they are only good for indoor use or evening use, since they can't trigger by radio when shutter pass 1/180s,
even though they can force hss power sync with light slave mode, but power recieiving on camera end is weak, and you limit to full power setting, which is to ensure full flash coverage during exposure, and godox give you all the power control in HSS,
even pentax AF540FGZ only give you -2 -1 +1 control in HSS mode. also the zoom on AF540FGZ only go to 58mm (85mm) comparing to morden flash zoom to 200mm these days. also recharge time for af540fgz is so slow compare to cheap yn560iii flashes