I wrote an article about using the Contax 645 lenses on the Leica S-E (Typ 006) as far as I know it's the only article going in depth with lots of sample images.
I felt it would be nice sharing it here.
You can read it here: http://jipvankuijk.nl/stories/
Let me know what you think either here or in the comments on my website! 😀