It features the Sigma SA mount and is designed to take full advantage of Sigma Global Vision lens. Superb optical performance.</br>There are two AF detection methods in this camera, and by combing these two into one single system, fast and precise AF is achieved.</br>There are two AF detection methods in this camera, and by combing these tow into one single system, fast and precise AF is achieved.</br></br>Product Description</br></br>Sigma SD Quattro is a high image quality camera that incorporates a mirrorless structure with APS-C size of the foveon X3 direct image sensor, generation name Quattro. This new lightweight camera offers the outstanding level of resolution in images.</br><br/>http://www.amazon.com/gp/product/B01HHR572O