Sony DSLR cameras can
use not only Sony
Alpha Mount lenses, but all Minolta AF lenses too. This opens up some
nice legacy glass lens options, especially for users on a budget. The
Sony LA-EA1 is an adapter for using these SLR lenses on Sony NEX E
Mount cameras, with some limitations. Auto-focus. It's best just to say
the LA-EA1 does not support AF, because when it does (SSM lenses only)
it's too slow to be useful. Unfortunately it also does not support OSS,
IS, VR or whatever else you want to call in lens stabilization.
At this point you might be asking what does the LA-EA1 do? It has a
solid, well built, easily removable tripod mount and maintains full
EXIF data. I like EXIF data. A lot. Enough for me to sell a Nikon mount
Tamron 17-50mm f/2.8 and pick up a Sony mount Tamron in conjunction
with the LA-EA1, so that I would know exactly what aperture and focal
length I am shooting at.
For the last forty plus years SLR cameras open lenses to their maximum
aperture until a shot is taken. Just before the shot is taken the
aperture closes to the selected value, the shutter opens and an image
is captured. Oddly enough, unlike any other mirrorless lens or adapter,
the LA-EA1 does the same thing. Unlike SLR cameras, there is a
significant delay after the shutter is pressed while the adapter sets
the aperture to its chosen value, then takes the shot. Less than a
second delay, but enough to make the camera feel like a glorified point
and shoot. Absolutely terrible for action photography.
I'm not sure what Sony was thinking with this process, as it's not
there in the far superior (except optically) LA-EA2.