More quotes below added since initial post.
Preface — there is a simple solution for me: ditch the Nikon 35/1.4G, and snap up the Zeiss 35mm f/1.4 Distagon as soon as it appears (I'll have one of the first in the country to review, and I already posted a preliminary review of the prototype). I can live without autofocus, certainly without autofocus that fails 90% of the time, so far has never delivered spot-on focus, not even for one frame. The Nikon 35/1.4G is a very sharp lens (comparison coming soon)., but there is no point owning a sharp lens that cannot be focused, unless one resorts to Live View with contrast-detect AF every time, or one masks the issue by stopping well down and praying.
I've emailed the senior product lifecycle manager at Nikon's New York facility, but the automated response looks like Jan 3 is the earliest that I could expect a reply. In the past, I have not been able to get an email or phone response. And I'm not about to send my D3x in for an interminable time frame and take down my ability to work for weeks.
Update! Testing this morning with another sample of the 35mm f/1.4G shows that it too exhibits the same focusing errors. Bot lenses are inconsistent, sometimes coming close, sometimes missing badly. Specific lighting conditions and subject matter influence the results, but there is also (sadly) enough variation that it's clear that no AF Fine Focus Adjust can ever guarantee correct focus except perhaps better average results. That this is true is immediately obvious in observing variation in results (on a tripod) each time the same test is made. Results also tend to differ if the lens is focused from beyond infinity to closer range, or vice-verse.
Following up on yesterday's report of Nikon 35mm f/1.4G autofocus errors, I have received two confirmations of the problem from other 35/1.4G users.
Reader Carsten B reports using AF-C mode (instead of AF-S), and having to invoke it twice when he notices (in the viewfinder) that it has misfocused, Nikon D3s:
With AF-C using only the AF-ON button for AF activation on a D3s.... Most of the time the AF focused perfectly, in a few instances it was totally off so looking through the finder showed immediately that correct focus had not been achieved (it was set at, say, 3 feet instead of 100)... I never use AF-S as I can simply keep the camera from refocusing by letting go of the AF-ON button.
Other readers have also reported better results with AF-C instead of AF-S. Using AF-C brings with it other issues— if anything AF-S ought to be superior, especially when set to Focus Priority. After all, if the implication is "focus once and be done with it", then AF-S ought to get it right as a priority.
Reader John G writes:
You wrote: "AF-C mode is a workaround kludge; using it as a workaround essentially admits a bug in AF-S." I think you're absolutely correct here. My experience supports this assertion. I am unable to get consistent focus in the AF-S mode with my D3X or D3, and experienced the same problem with a rental D3S. While I haven't conducted any formal tests, I believe this has become more of a problem with Nikon's new crop of F/1.4 lenses -- especially with the 85mm at distances beyond fifteen feet.
As I think about it, I have a 200mm F/2 AF-S VR (older version), and never remember experiencing this problem with focus in the AF-C mode when using that lens. In fact, I always marvel at the D3/200mm combination to nail focus at F/2. Could it be that there is a problem with Nikon's algorithm in the AF-S mode in conjunction with these new lenses? If so, could this be fixed with a firmware update? How does Nikon typically respond when you uncover these kinds of problems, especially in this case where a number of readers confirm and verify your findings? A more disturbing question: Why is Nikon not catching these problems before they release these new very expensive, ostensibly professional products?
DIGLLOYD: Unfortunately, AF-C is not fixing the problem for me, though it might be a little better than AF-S. Both are variable under controlled circumstances.
Reader Frank W reports troubles similar to what I'm seeing; I advise him to try AF Fine Focus Adjust (I am still researching whether that works across the focusing range). AF-C mode is a workaround kludge; using it as a workaround essentially admits a bug in AF-S.
Thanks for your review of the new Nikon AF-S 35mm f/1.4G. You are right! After checking my copy I received last week I must admit it is the worst lens I have ever bought in respect of autofocus! I can fully confirm your findings so the lens is unusable for me. First I was a bit unsure about it, as my 24mm copy works fine, but that 35mm lens is a nightmare!
Reader Thorsten K reports his take on how the 35/1.4G has performed:
I took 80 shots on the playground the other day, and about 20 are badly out of focus, by as much as a foot. Sometimes front, sometimes back, it's erratic. One could write it off as my kids being in motion and the AF not fast enough to follow, but then again the 24/1.4 and 85/1.4 give me almost 100% in focus shots under the same conditions. My kids are not sprinting around, just moving the body slightly while playing in the sand etc. I was actually surprised how well the other lenses focused, given their slow AFS motor. With the 85/1.4 I can even track them on the swing and get all shots in focus, not so with the 35/1.4.
From the in-focus shots from yesterday, not all of them are completely dead-on either. Some are what I would consider good if shot with a lesser lens like the 50/1.4 and they are certainly good enough to put on the web for the grandparents, but the 35 is so sharp when it nails focus that it annoys me when not all shots are like that. And again, the 24 and 85 nail almost every shot with my kids.
But in general, it's still too early to tell. I will need more practice to see how the AF works for stationary vs moving subjects so I can isolate the issue. Oh, and all my kids shooting is done with AF-C mode. I maintain the focus point on the eye and keep pressing the AF-ON button for some time to give it enough time to focus. That's how I achieve close to 100% with the 24 and 85, but not so far with the 35.
Reader James K makes some suggestions which in my view head out on a wild good chase. I format my cards every time, and two pro bodies ought to work. And I don't have a fresh Nikon D3x body lying around, and I have 10 or so SanDisk card, which I always format in the body. But I want to be clear: my working theory is that this is a Nikon AF system bug, a fundamental algorithmic flaw in focusing f/1.4 Nikon lenses, not a lens issue. I could be wrong, but I've never had such problems with Canon AF.
Your system might be contaminated in some strange way. If you get a fresh Nikon D3x body ( factory presets) and a new SanDisk card formatted in the new body and the behavior is the same then you will know it is the lenses.
Try and think of any software conflicts. As you know these systems are very complex and Gremlins just love that environment. Maybe multiple adjustments to your cameras has produced a Nasty. Contaminated CF cards shared by bodies- lots of possibilities. Remember I had a similar problem with a relatively simple film camera, my new Nikon F6. Never resolved- had to sell the camera and the Gremlins with it.