An Anamorphic "Anamorfake" adapter for the Sigma 18-35mm f/1.8. Should work on any Sigma or Zeiss Distagon lens, not tested yet! 
 
How to install: https://youtu.be/uwrX821VY-s 
 
DISCLAIMER : We are in no way responsible for ANY damage on your lens/camera/adapters. There shouldnt be any additional force required to mount this on your camera. If you feel any resistance, DONT mount it and check if any screws or pieces of plastic are pertruding.