This solves the lens availability issue and works perfectly!
21 December 2013
Summary: I got this product a week ago and I upgraded my SLT-A77 to A7R and keep mySAL2470Z SSM CZ lens and SAL70400G SSM, focusing is same as as when I have them attached on my SLT-A77..It actucally feels faster..Weird..The only thing missing is the stabilization..since sony does not make there stabilization much on the lens, im out of luck but honestly I tested it wth telephoto and I dont notice the difference.
Summary: Finally Sony introduces a full-support E-mount adapter for full-frame cameras/camcorders that allows mounting A-mount lens; and supports both AF and FF with a full-size translucent mirror for accommodating full-frame sensors. Its electronics supports auto-focus and zooming on motorized A-mount lenses. This LA-EA4 supports both single-shot AF and continuous AF. I bought mine for my NEX-VG900 camcorder and like it.
Great and east to get going, unsure of the continuous auto-focus, needs more testing.
Gaurav Gandhi, Amazon
2 December 2013
Summary: Works as expected. Not sure about continuous auto-focus mode, still have to do more testing. I am using it with a Sigma 35mm f1.4 (art line). Will post an update, once I use it more. What lens are others using?