Wed 14-Nov-12 01:43 AM | edited Wed 14-Nov-12 01:46 AM by rplst8
My camera arrived at Nikon's facility in Melville on Friday (the 9th) for the 3rd time. Shortly after lunch I got a voice mail (and email) from a Nikon customer service manager (CSM). Someone seemingly pretty high up based on their title, but I'm not naming names.
The voice mail said basically that during a quick test (similar to mine) he could not reproduce the problem. He submitted some sample shots and I quickly examined them in ViewNX 2. I called him back and conceded that his examples were better than my testing, and we talked briefly about the situation. We noted that the only real difference in our tests was that I was under tungsten lights and he was under fluorescent lights. I also noted that the images were taken at 1/80 while mine were taken at 1/1600 or so, guaranteeing that any vibration wouldn't likely affect my images. The CSM said he would ship my camera back promptly and that was it. There was not much to say really, and at this point I sort of felt like an idiot.
During the weekend, I took a closer look at the images he shared and I noted a few discrepancies. First, at no time was the AF fine tune used (as was used in my samples). Second, some samples were of a test chart (much like mine) taped on an office whiteboard. In the sample for the center focus point, I noticed some red/purple CA on the blackest parts of the test chart (indicating less than perfect focus). Third, at no point was the actual center focus point used. In one set of images, a lens align tool was used. The leftmost and rightmost focus points were used, but one just to the left of center was used for the "center focus point" example. In another set of images, the row of focus points above the middle row was used (so, leftmost, center, and rightmost on the row just above the middle row).
After gathering this information, I replied to the email (through the MyNikon service portal). I received no reply yesterday, but my camera and lens were checked into Nikon service and I got an email stating that fact. Today, I got a another reply through MyNikon from the CSM stating that while he did use a different sent of focus points, he did so because there was no acceptable detail to focus on when he set up the test under the focus points I used. So rather than raising or lowering the camera (or moving targets) he just used other focus points. He stated that there would be no difference in the performance of the auto focus system due to this.
In my previous reply I also noted the difference in the type of lighting used and I wondered if that might factor in. The response to that was basically that while different color light has different characteristics, Nikon does not publish any specifications for their auto focus systems related to this fact.