One of the most intriguing things about the Sony Alpha NEX-5 and NEX-3 cameras is that you can use your existing A-mount lenses on the new models. Well, sort of. You need the Sony LA-EA1Â adapter to mount an A-mount lens on the NEX system, and that involves some minor sacrifices. Overall, however, your current lenses should deliver great images on the NEX system.
The LA-EA1Â is a far cry from the simple adapters used to mount non A-mount lenses on the Sony Alpha. It differs from the typical simple machined ring found inÂ MC to A-mount adapters or M-42 lens conversion mounts. The A-mount to NEX adapter is a sophisticated piece of electronics.
Unlike Minolta Rokkor or M-42 lenses, A-mount lenses from Sony and Minolta do not have an aperture adjusting ring, Older style lenses have a mechanical ring that allows the user to change the aperture opening manually. When Minolta introduced the Maxxum cameras in 1985, however, they did away with the aperture ring and used electronics inside the camera to regulate the aperture. If desired, the photographer could still manipulate the aperture manually, but it had to be done through a menu on the camera body.
This makes a conversion adapter for A-mount lenses more challenging to design. Conventional adapters rely on the user manually setting the aperture. Since there is no external method for changing the aperture on an A-mount lens, any useful adapter needs to provide a way for the camera to actually control the lens electronically.
Admittedly, it isn’t difficult to pass electrical information through an adapter. but the adapter needs to be designed so the camera’s aperture control can control the lens.
The LA-EA1Â can do just that, providing automatic — and presumably manual — control of the lens from the camera’sÂ controls. Since the auto-diaphragm on the A-mount lenses is also controlled electronically, the new adapter will provide auto-diaphragm capability as well.
What the adapter will not provide, however is auto-focusing. The overwhelming majority of A-mount lenses do not have internal focusing motors, so the adapter is not designed to offer auto-focus.
The other limitation is image stabilization. Sony Alpha dSLRs are famous for having image stabilization built into the body. In order to make the NEX bodies as small as possible, however, Sony engineered the small cameras to use in-lens stabilization. As a result, A-mount lenses mounted to the NEX series cameras will not have stabilization.
One other interesting feature of the adapter is the built-in tripod collar. The NEX series cameras are so small that there might be problems using a heavy lens on the camera while it is on a tripod. Sony eliminated the problem by incorporating a standard tripod mount within the adapter. You merely hang the camera body on the adapter, while all the weight of the lens is borne by the adapter.
The LA-EA1 is available for pre-order at Sony Style for $199.00.