My three prime lenses (50mm f1.8D Nikkor, 180mm f 2.8 Nikkor ED,& Tokina 100mm 2.8 AT-X Pro)have stopped auto-focusing on my D700. However all three of these prime lenses continue to auto-focus on my D800. My nikkor 24-70 2.8 and Nikkor 16-35 f4 and 70-300 ED AFS 4.5-5.6G (All zoom lenses) will auto-focus on both cameras. All of the primes will manual focus of course and are very sharp lenses. I know this sounds crazy, my firmware is current but I've run out of settings to change. Any ideas? Thanks for your suggestions Tom ireton
#3. "RE: Can't autofocus with prime lenses " In response to Reply # 0
As the first reply noted, the three lenses that won't AF are all "screwdriver" AF models, which are driven by the AF motor in the camera via a mechanical connector. It could be that the camera's motor has failed, but a simpler explanation is that the little connecting lug in the camera's lens mount has jammed and is not extending as it should to engage the corresponding "socket" in the lens.
This isn't likely to be an electrical contact issue.
#4. "RE: Can't autofocus with prime lenses " In response to Reply # 3
La Paz, MX
Thanks to all of you. I had no idea that there was an auto-focus motor in the camera and had never seen the little lug protruding from the lens mount plate.( Until now) I can hear a click, click sound when I try to auto-focus with the primes and suspect that after maybe 30 to 40,000 focus' the poor ol' motor may just be tired as suggested. This sounds like it calls for a trip to the Nikon repair facility in Los Angeles and shipping things from one side of the border to the other (and back) has it's own special set of challenges when you live here in Mexico. I suspect that for a while at least I'll use the other three lenses on it and use the D800 when I need one of the primes. Thanks again for the suggestions, once again Right ON! Tom Ireton