Nice combination! The Scarlet Tanager was shot hand-held through a window at about 25 ft. The wild turkey was at least 200 feet (60 meters) away, hand-held but braced on a window sill, 500mm, 1/250 sec, f/8, iso 160. Couldn't do this with my old D80!
It says on the Nikon website that only the very center focus point is compatible with lenses slower than f5.6.
Just wondering if the body actually turned the others off, or that was just a guideline, According to Nikon none of the focus points on my D5100 are supposed to work below f5.6, but all work fine with my 50-500 OS
Mon 13-May-13 11:48 AM | edited Mon 13-May-13 04:30 PM by TomNJ
Ah, I get it. I just did some experiments using off-center focus points, which all worked. Outdoors in bright sunlight the subjects snapped right in. Indoors in lower light it depended on how contrasty the subject was. For most subjects the focus was fast and spot on. With lower contrast subjects in lower light there was some occasional hunting, but the off-center points still worked and focused within one second. In a few cases with particularly difficult subjects the off-center points just couldn't focus at all, while the center point consistently nailed them. So there is a difference, but not meaningful for most situations. F/6.3 is only half a stop slower than f/5.6 so I would not expect to see much difference from off-center focus points, except with those rare very low contrast low light subjects.
I have the 50-500mm OS and it is even better with the D7100 than it was with my D7000. That said, that applies to just about every lens I have and probably down to the absence of the AA filter. Seriously though, for the money the quality is excellent