You asked
Best camera for the sigma 85mm f 1 2 dg art?
For most people I'd pair this lens with the Sony a7 IV. It's a full-frame all-rounder, so the 85mm frames as marked and you get the shallow depth of field this lens is built for.
If you mostly shoot portraits and want room to crop tight, the Sony a7R V gives you more resolution. If you want something smaller to carry all day, the Sony a7C II keeps the same full-frame sensor in a compact body.
On APS-C, like the Sony a6700, the lens frames like about 128mm, which is a lot of reach for tight headshots from further away. That's a good trade if you want distance. The portraits guide has more on choosing focal length.
Written by Claude from this site's pages.