Why not a f/2.0 which is becoming pretty standard for high performance "compacts"?
 
(Chuck W) - This time, one of our objectives was to balance the size of the camera with the zoom ratio. We felt that having a 4x wide angle zoom on this camera at f/2.8 is the same aperture as we've been dealing with since the G7. We think that the other improvements far overshadow the aperture, especially when you look at the ISO up to 12,800.
 
(plus loin)
(CW) - Again, it's just a tradeoff between the size of the lens and the size of the camera. We settled on a 4x zoom ratio; if we'd gone with 24mm, the telephoto end would have been compromised. We decided that there was more demand on the tele end than for going to 24mm vs 28mm.
 
Is zooming speed variable?
 
Chuck: No

Hi Chuck, can you talk about the low-light capabilities of the G1X sensor? For example, how is the noise at 5600 ISO compared to the 5D2? Thanks
 
(Chuck W) - Closest comparison is to cameras like the 7D and 60D, because it uses the same pixel pitch. The G1X is actually lower noise than the 7D, because it's the latest generation of the DIGIC, the DIGIC 5. Can't speak to RAW because I haven't seen it, but the JPEGs and videos are definitely cleaner at any given ISO than the 7D's. I can speak to that personally because I tested it myself.

Hello please say can i enable manual control in video mode on g1x (shutter, apperture) ? Can i control ISO in video?
 
I haven't had a chance to check on the ISO question, but there is no Manual control over video exposure.
 
Hello, I was wondering does the built in nd Filter work with video? What are the Settings/Frame rates for Video. What resolution do you have to go to to get 60f?
 
(CW) - yes, the ND filter works with video. Not 100% positive, but the best of my recollection, I believe that the 1080p tops out at 24p. The 720p does allow 60p or 50p.

Can you comment on autofocus speed as compared to previous G series and even perhaps dSLRs?
 
(CW) - it is a contrast detect AF like prior G series, but the speed is a bit faster than the G12 in most cases. The only time when that might not be true is in extreme macro situations.
 
(plus loin, le T3i c'est le 600D)
Comparing the contrast-detect performance of the G1X vs the contrast-detect performance of the T3i and S100, the G1X will be faster than both. When you're looking at the phase detect performance of the T3i, the T3i will come out ahead.

Will you be able to use a cable release on the G1X?
 
It's compatible with the RS-60E3 release. It's the same one we've been using for awhile.

Is the filter adapter 58mm?
 
(Dave E) - Yes, the front-element threads are 58mm.
 
(...puis, en examinant l'appareil )
(Dave Etchells) - Correction on the front-element threads. The adapter that mounts to the bayonet ring has 58mm threads. The threads on the lens itself are smaller; we don't have a spec here for their size...