Though Canon says you will need a camera body made in 2011 for High Shutter Speed Sync, my tests show older camera bodies will work in this mode. Above is the display of the ST-E3-RT that is attached to the hotshoe. I set shutter speed to 1/8000 sec and shot off a frame. The resulting frame looked under exposed but was in sync meaning the entire frame was exposed. I suspect in that mode, I will have to go into my E-TTL setting and add more light selecting “+2” or even “+3” to compensate for the light loss or else switch to Manual mode and increase the power ratio.
High shutter speed sync is the mode that many photographers using Speedlites rave about but in practice its applications even with the latest greatest Canon bodies is limited.
