Morten Engelien

The sensor of the A7s wouldn't resolve full HD anymore if you crop from full frame 35mm (36 x 20mm in 16:9) to Super 16 (12 x 7mm); the factor 3 crop would reduce the camera's video resolution from 4K to 720p. 

 

AFAIK, the camera offers no such crop mode in-camera, but you can always mount an adapted s16mm lens, shoot 4K with vignetting and crop the recorded image to 720p in post.

Ah, okey!  Thanks for letting me know. 

Can i use my super 16mm lenses on the new Sony a7r?  Is there a crop-mode small enough for s16mm in-camera?