Unless otherwise needed, i will not use auto ISO.
go to flash control and disable flash firing, or you can switch on the HSS button on st-e2
Any reason Bro?
For me, this is one of the important features. It will adjust your shutter speed to reduce the hand shake. Also, the ISO will be adjusted in 1/3 stop (instead of 1 stop if you use normal setting). With this, I can concentrate on the aperture (no need to worry about blur due to the hand shake).
Not really useful, since the 1/3 stop increments in ISO are either pushed or pulled from full ISO stops in-camera. Just set your ISO accordingly, then focus on the aperture.