I am curious about the D5's AF system's accuracy with F1.4 lenses as compared to the D4. Has there been any improvement in this regard?
Thanks and Regards
the answer is the usual yes and no
Depending of the lens/camera combo, the D5 is sometimes like a few of my other bodies off the focal plane with a few fast lenses (Please consider that Nikon calibrates AF systems with a 50mm/1.4 reference lens set at f2.8. I heard this back in 2011). I had a few of my bodies and fast lenses travelling mutiple times to Nikon's service facility in Dusseldorf in 2011 (the whole process took more than 2 months and brought forward the spectral sensitivity of AF systems built into the D3/D3s/D3X/D7000, plus a few other gimmicks. The spectral issue had been fixed in the D4/D800 generation. More info on this exercise
in german language). This is the bad part.
The good part is, that fixing it with the D5 is a sneeze vs. the previous cameras.
The Auto AF fine tune is described in the Menu Guide on page 110 (The Menue Guide is only available as PDF, it is not in the box. There is only the User Manual as printed doc)
Correcting the AF of a lens takes about 5 seconds (*) if you have a proper target (i.e. a vertical plan sheet). The AF is then not "perfect" in the pixelpeeper sense (neither is the Live View AF always 100% correct at this level), but it is as simple as to be very valuable that you can do it on the fly when needed.
(*) 5 seconds is now the time it takes to set AF when the camera is on a tripod. It is really simple.
My first attempt took roughly 30 mins, I was close on raising a service request for help
1) I couldn't find the AF fine tuning button sequence in the user manual. There is no mentioning on auto AF fine tune in the D5 User Manual.
2) There was info in the internet that the button combination was (AF-mode) and (shutter release) - but that didn't work ...
3) When I figured out that it was covered in the downloaded Menu Guide, the right button combination to press is "AF-mode" and "Video-Rec"
4) Then the error message popped up every single time "Auto AF fine tune is not available at current focus setting" and didn't let me store the adjustment value
5) The culprit was the focus selector in LiveView mode: It has to be *exact" in the center of live view field. Putting it approximate there doesn't do the trick. Pressing the OK button in LiveView to put it perfectly in the center did the trick and brought me over the finish line that I could store the AF compensation value.
6) Now it is really a short and convenient process