Blog by Spencer Lookabaugh.
One of the major advantages of the Sony mirrorless E mount is the super-short flange focal distance. The distance from the mount itself to the sensor is one of the shortest of any mount in use today (See: Flange Focal Distance). With the use of an adapter, almost any lens can be used on a Sony E mount camera. The adapter acts as a spacer to mimic the mount-to-sensor distance (flange focal distance) of the mount that is being adapted to the Sony. Practically any lens can be adapted to the Sony E mount, making the lens possibilities almost endless.
One of the most popular mounts that we see adapters for, is the Canon EF mount. There are also several Nikon F mount adapters in the works that aim to provide the autofocus and focus speed that users are used to. Sigma Corporation of America, the company widely known for their incredible Art Series lenses, has created what may be one of the best adapters on the market.
What is different about the Sigma adapter? The difference is in the language that this adapter speaks. Aside from the difference in the physical bayonets, there is an electronic language or signal that cameras and lenses use to speak to each other. Sigma’s MC-11 Adapter is the first adapter that serves as a translator for this signal. This allows for the use of tracking features like face detection, continuous focus, and quicker autofocus speeds. Other adapters on the market simply send the lenses information to the body, most of which the Sony cameras don’t understand, making for a less-than-desirable user experience as many features of the camera are disabled.
From the Sigma announcement of the new Sigma MC-11:
“There are many challenges to designing high-quality mount converter and topping the list is aptly handling phase detection AF in newer cameras and this is where the Sigma MC-11 is groundbreaking in its support for the Sony E-mount systems,” states Mark Amir-Hamzeh, president of Sigma Corporation of America. “The new Sigma MC-11 mitigates complications with a purpose-built lens control data system engineered for maintaining superior AF functionality. So the growing number of Sony E-mount camera users who have been asking for more lens options, now have access to a large pool of lenses that fully embody Sigma’s signature quality and performance.”
The Sigma MC-11’s sleek LED display lets Sony users know if the attached Sigma lens is compatible and whether or not the MC-11 needs to be updated for that specific lens. Its internal control data system keeps detailed information on each compatible Sigma lens, automatically optimizing performance of AF drive, aperture control and other critical lens functions. The MC-11’s internal control data system also maintains continuity with key camera functions that control brightness and correct transverse chromatic aberration, distortion, and more. The complete compatibility with both Sigma lens OS and Sony in-camera OS ensures correction of camera shake and other stability issues and when used with in-camera stabilization, MC-11 allows angle shake correction in the lens. The integrated flocking helps prevent internal reflections and reduction in lens performance. In addition, the MC-11 retains important EXIF data ensuring users can analyze every detail of their lens setting.
Sigma’s MC-E11 adapter provides the compatibility that I have always wanted out of E-mount adapters. It really doesn’t even feel like I’m not using a Sony lens on the camera. Even in lower contrast/dark environments, the MC-E11 was able to keep up with the Sigma 50mm f/1.4 and Sony A7sII. If you are looking to jump ship to Sony, now is absolutely the time.
Note: These new adapters are meant to work only with the Sigma Global Vision series of lenses (Art, Contemporary, and Sport). With the Canon version of this adapter, it’s intended use is for the Canon mount Sigma Global Vision lenses.

Sigma Global Vision Lens Compatibility Chart