While digging around the bowls of the internet looking for solid information on Canon and Nikon AF systems, I came across Nikons own official page on their 51-pt AF system. I found the following blurb (from http://www.nikonusa.com/Learn-And-Explore/Nikon-Camera-Technology/ftlzi4pn/1/51-Point-Autofocus-System.html
With the new Nikon D4, the AF maintains the power of the five cross-type sensors in the center as long as the combined open aperture value is below f/8.
I've emphasized the most important part. The Nikon 51-pt AF system works with the five cross-type sensors in the center as long as the maximum aperture is BELOW f/8? Where exactly does Nikon say their AF system supports f/8 autofocus? Where exactly is the information that declares the D800 or even D4 capable of even center-point AF with a maximum aperture of f/8?
For all the hullabaloo about how the 5D III and 1D X are inferior to the Nikon offerings...I'm not sure there is actually any evidence to support the idea that Nikon cameras can AF AT
f/8. That would at best put them on par with Canon's new AF, and they are certainly trailing behind in the area of higher-precision cross-type points (15 with Nikon's 51pt AF system, vs. 41 with Canon's 61pt AF system.)
So...where exactly is f/8 AF for Nikon?