Hi Guy,
I am pretty sure that the GM lenses are designed for the short flange FE-mount so I think it would need a different design for the A-mount, that has a flange distance making place for the mirror box.
My take is that the E-mount system uses a combination of phase detection for speed and contrast detection for accuracy. The contrast detection needs very fast focus corrections, so the new lenses use either linear motors (linear USM or steppers) or voice coil designs.
The adapters, except the LA-EA4, probably just hook up electronics in the lens with the E-mount.
Personally, I am not that much interested in fast lenses, but that is just me...
Best regards
Erik
If Sony was smart and took both GM lenses and updated them to this A mount. Took there 135 mm and updated it to SSM. Improve there 35 1.4 than you would see a lot of folks jumping on it. My big concern is their lenses and if they are updating them or not. If they actually said or gave us a roadmap it go a very long way in buyer confidence. Their lack of commitment to this A mount has hurt them from a buyers seat. It's a exciting camera no question but I think if they really want sales than make some announcement about the lens future. We have the FE mount and they designs for those GM lenses in p,ace right now, so what would it take to make them in A mount. There new FE 50 1.4 is killer make it now in A mount. Also give us new adapters from A to E that take full advantage of the FE bodies AF system