Best portrait lens for the nikon d810?

For portraits on the D810, I'd start with a fast 85mm. The portraits page makes the point that lens matters more than body here, and the lenses page lists an 85mm as a good addition for portrait work.

• Nikon AF-S 85mm f/1.8G: my everyday pick. Small, sensible, and very good for the money.
• Nikon AF-S 85mm f/1.4G: if you want more background blur and low-light room.
• Sigma 85mm f/1.4 DG HSM Art: a sharp, fast option if you want to step up.

Whichever you choose, light beats gear: face a window and expose for the face.

Written by Claude from this site's pages.