I recently bought myself a pack of four YN560 IV's and a YN560-TX for my Canon camera, and apparently I got ahead of myself and didn't realise I should make sure the flashes support HSS.
I tried them out yesterday at home, and even on 1/128 and 1/250s on the camera, they were overexposing here and there. Unfortunately, I don't really have the space to move the flashes much further from my subject, so I was wondering if there is any way to trick them into HSS? I should mention that I also own a Canon 580ex II, which does support HSS. I was thinking I could perhaps use that mounted on the camera to trigger the Yongnuo's, but as far as I can tell that would render the 560-TX useless as the flashes can't be controlled wirelessly when in S1 or S2.
I guess I could buy an ND filter, but as I have lenses with differing sizes, this feels like more of a pain in the ass.
Is there any hack I can pull off here that you guys know of?