andrewz

I have both the D7200 and D810. I think you will find the D810 focusing performance and functionality to be similar (actually a little better) to the D7200. I use the Sigma 14mm f/1.8 Art lens on both and have no problems on either camera. For sports photography, I employ the D810, 70-200 E FL ED and 3D tracking. It works great in that application. I have not used it for portraiture (in the way that you describe), but I suspect it would do well if you lock onto the eye of our subject. Hope this helps. Reach out if you need more info.