By: Arthur Morris/BIRDS AS ART

Arthur Morris/BIRDS AS ART — Tue, 11 Jun 2019 14:01:43 +0000

I understand what you are saying but the “closest point” had to be the base of the near-wing which conveniently happens to be right on the same plane as the eagle’s eye. That said, I have seen Group yield sharp images in situations where the array was surely nowhere near where it should have been …

with love, artie

By: Gary Shackelford

Gary Shackelford — Tue, 11 Jun 2019 13:55:21 +0000

If you were in Group autofocus mode and the center of the Group array was positioned as you describe, it makes perfect sense that the eye was razor-sharp. From what I have read about Nikon’s AF system in its modern cameras, including the D850, in Group mode the autofocus system effectively treats the entire group of AF points (13 points in the D850’s 153-point system) as one large autofocus point, and it is the camera, not the photographer, that selects the priority AF point. This point is typically the one that is over whatever is closest to the camera, and in the case with your eagle it was probably the point over the eagle’s beak or eye. You don’t see all 13 AF points in your viewfinder. The 4 visible points in the viewfinder merely serve as a guide for the boundaries of the 13-point array.

The AF behavior in Group mode (and all other AF modes) will also be affected by the custom setting Focus Tracking with Lock-On (a3 in the D850), which controls how long to hold autofocus should all of your Group array points fall off the subject.

Comments on: Basket Lake: It Ain’t Just Moose! And An Underexposed RAW File Conversion Workflow Tip

By: Arthur Morris/BIRDS AS ART

By: Gary Shackelford