Best portrait lens for the sony a9 iii?

For portraits on the a9 III, I'd start with a fast telephoto zoom, since it gives you room to step back and keep the background soft:

• Sony FE 50-150mm f/2 GM is my top pick. It's fast, and its focal range suits head-and-shoulders work.
• Sony FE 70-200mm f/2.8 GM OSS II is the one to choose if you want more reach and a little more distance from your subject.
• Tamron 70-180mm f/2.8 Di III VC VXD G2 is a lighter, slightly cheaper way into the same f/2.8 look.

Whichever you pick, the light will do more than the lens. Put your subject near a window, turn them a little, and expose for the face. See portraits and light beats gear.

Written by Claude from this site's pages.