Sigma has just released a new firmware Ver.1.18 for Sigma MC-11 lens adapter. Click Here to download. See the detail below: It has improved the AF speed when it is used in combination with the SONY α9 or SONY α7 III and the SIGMA 135mm F1.8 DG HSM | Art for SIGMA.Note: For customers who own the SONY α9, please update the firmware of the camera to Ver.5.00 or later.