You asked
Best portrait lens for the sony a6700?
For portraits on the a6700, I'd start with the Sony FE 50-150mm f/2 GM. It covers about 75-225mm on full frame, and at f/2 it blurs the background beautifully while keeping faces sharp. It's the most portrait-friendly lens on the body's list.
If you want a little more reach, the Tamron 70-180mm f/2.8 Di III VXD G2 is a fast telephoto zoom that frames tight headshots nicely. For more of the scene, such as a person in a room or at a market, the Sigma 28-45mm f/1.8 DG DN Art works well.
The 85mm-equivalent I usually recommend for portraits works out to about 57mm on this body. I don't see a fixed lens at that length in the a6700 list, so the zooms above cover that ground.
Whichever you pick, light matters more than the lens, so read Portraits before you spend.
Written by Claude from this site's pages.