Using SLR (35mm film) lenses for cinematography?

The Scarlet won't be out for years, and a functioning camera will be more like $15,000. Yes, you can use an all manual SLR lens, you obviously need a depth of field adapter- I prefer the Cinevate mp.1 model. Many people, including me, successfully use this set-up, but remember- Cinema and SLR 35mm are different formats- so an SLR 35mm is more like a 50mm, so you have to adjust accordingly. Also DoF adapters can be somewhat tricky- you constantly have to adjust them to get the best performance- make sure you get yours well before production and do plenty of tests.