However, you really don't need anything faster than 1/400 heck 1/250 is fine even for stop motion work unless its a bullet...
If you're already taking the time to set lights and meter etc, then throwing on an ND filter for a super bright scene if you want a more shallow depth of field is really not that hard.
You really only need 1/1000+ speeds when your out doing documentary work or sports photography etc when you're changing settings on the fly IMO.
I'm sure there's some rare case you need faster, but for the most part it's not needed so as long as it syncs to 1/400 you're fine. And focal plane shutters usually don't sync faster than 1/250 anyway unless you use their "high speed sync" features which I believe create a longer more extended flash that fires BEFORE the shutter moves and the burst lasts through the whole shutter movement rather than firing the flash and shutter at the same time, so you lose a lot of power with the high speed sync, and also, again, don't usually need it.
If any of that is incorrect, please correct me, but that's my understanding.
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