Can I use the power zoom 16-50mm on first generation Nex-5?
Luc de Schepper: Of course Sony shared the E-mount specs with Tamron. Sony has a 11% share in Tamron and they (Sony) benefit from more NEX-lens support. I wouldn't be surprised if the current non-Zeiss labeled NEX-lenses are all made by Tamron.
E-mount spec is shared by Sony to manufacturers of lenses and mount adaptors for free in case you missed the news last year