Just to stir the mud a little more, the G12 will sync without using HSS at 1/4000th although for some odd reason not with the ST-E2 where it's a little slower. It's left me wondering the kind of shutter the G1X is going to have, focal plane as per the NEX or electronic like the G12.
Does the G1X have a focal plane shutter? My guess based on the above is no - a 1/4000 sync speed means electronic 'curtains'.
I used to have a Sony compact that also synced at 1/1000s and froze action like nothing else. I understand how the shutter of an SLR works, but I have never thought of what the negative sides to an electronic "curtain" is? Can someone fill me in? Why doesn't the slr's use electronic "curtains"? You could still have the mirror and everything, right?
Lag is the reason for a focal plane shutter. Compact cameras continually read image data from the sensor when the shutter is pressed the sensor has to first be cleared, then allowed to expose for a set period before it's read & then wiped again, it all takes time, not a huge amount and compact cameras are much more responsive than they used to be, but still nothing like as fast as a DSLR.
Neuro I think you miss read my post, I can get the G12 to sync at 1/4000th I've no idea what the G1X will sync at just wondering as it has a much bigger sensor, and the NEX which is the nearest equivalent does use the focal plane shutter (and very noisy it is too!)