You asked
Best 85mm lens for sony full frame?
For most people, I'd start with the Sony FE 85mm f/1.8. It's the portrait lens I'd buy first on Sony full frame, and the portraits guide explains why 85mm is such a flattering focal length: it keeps you at a comfortable working distance and gives soft backgrounds.
If you want a faster lens and can justify the extra cost, look at the Sony FE 85mm f/1.4 GM or its successor, the Sony FE 85mm f/1.4 GM II. Those are for low light and very shallow depth of field. I don't have enough on this site to say which of the two f/1.4 versions is better, so check the individual pages before you choose.
Written by Claude from this site's pages.