Nate’s Film Tutorials:
The Sigma MC 21 adapter does not allow you to use the full frame sensor because it tells the camera it is an APS-C lens. I figured out a “hack” so you can use your Sigma 18-35mm on your Full Frame Panasonic S1 and S1H Camera. It even allows electronic control of aperture and autofocus, however it is not ideal because when you turn of the camera it resets to Super 35mm (APS-C) Hopefully Sigma or Panasonic can fix this issue.