Quote Originally Posted by jrw View Post
There was a section in a press release that talked about using with a 2x TC but the details on AF were lacking. Not sure if that means the built in 1.4x TC wasn't in use to be under f8 AF limit or not.
Rouse addressed that. With the internal TC in use and a 1.4x mounted, you've got f/8 and thus center point AF on capable bodies. With a 2x mounted and the internal TC not in use, again f/8 and AF on capable bodies (and two 1.4x equals a 2x, would be interesting to see which gives better IQ). With the internal 1.4x engaged and a 2x mounted, f/11 and no AF (although Live View would work).