A77M2 Specs Correction
In the autofocus section of the A77M2 Hands-on there is "Contrast Detect (sensor)" listed as a focusing mode. This camera doesn't use contrast detect at all and this should be removed.
But that is true is it not? Doesn't the camera still use CDAF (Contrast Detect Auto Focus) when LiveView (mirror up) only focusing with the main sensor? Otherwise, I would think the camera couldn't focus in movie mode as the mirror is up and not directing light to the PDAF sensor.
No CDAF - ever. The SLT series of Sony cameras uses a partially reflective "fixed" mirror
Fixed mirror...forgot, thanks. Wonder if "Contrast Detect" (sensor) has a different meaning. Correction certainly needed, perhaps. Good catch
to continuously direct a fraction of the incoming light to a PDAF focus sensor (it can be moved out of the way for sensor cleaning). The remaining light lands on the imaging sensor for still and video recording and viewing by an EVF. This allows PDAF focusing during Live View and video without the mirror moving at all which makes it a different animal from DSLRs.
The Live View system used in DSLRs is kinda clunky in comparison. The downside to having full-time PDAF is the imaging sensor gets about 1/2 stop less light.
You would also lose the "Perfect" focus capability that CDAF offers and lose AF in movie mode shooting small apertures. Pros and Cons.
My opinions are my own and not those of DPR or its administration. They carry no 'special' value (except to me and Lacie of course)