Sony Alpha NEX NEX5K Digital Camera with Interchangeable Lens
The NEX-5 along with its sister, the NEX-3, and also the Sony Handycam NEX-VG10 use a new lens mount system developed by Sony for NEX series and known as the Sony E-mount. Initially, there were three available lenses: an all-purpose 18–55 mm lens, an ultra wide pancake 16 mm lens, and a wide range 18–200 mm E-mount lens.
With the post-November 2010 firmware version 3 installed, and by using the (roughly 200 USD) Sony LA-EA1 adapter, the NEX series of cameras is able to electronically control the aperture and autofocus of Sony SSM/SAM A-mount lenses, and control the aperture of the other Sony/Minolta A-mount lenses with manual focus only. The (roughly 400 USD) Sony LA-EA2 adapter also supports autofocus with screw-drive A-mount lenses, firmware version 5 is required for this adapter.
Other third-party mechanical tube adapters are also available. These adapters enable the use of Canon FD-mount, Canon EF-mount (without aperture control), Contax G, M42 screw mount, Minolta SR-mount (MC/MD), Leica M and screw mount, Nikon F-mount (non-G), Pentax K-mount (non-DA), T2 screw mount and Minolta/Konica Minolta/Sony A-mount lenses. The E-mount flange register is so short that it is possible to mount 45mm or longer-focal-length non-focusing enlarging lenses on the NEX body, with the use of an intermediate focusing helicoid behind them.