Hi all, My D3 has been to Nikon USA twice now with an autofocus problem. Occasionally the autofocus will just lock up and refuse to function. It's not a low contrast target problem. If the lockup occurs I can swing the camera to any target and it still refuses to autofocus. Then, for no apparent reason, autofocus will resume.
After Nikon techs were unable to replicate the problem twice in a row, after a charge of $420 plus shipping and tax for the repair that never happened, after shipping the camera to them twice for a total charge of about $110, I decided to do a bunch more testing to see if I could find a way to get autofocus to reliably lock up.
What I found was that with my zoom lenses, if my hand was on the zoom ring the lockup would happen randomly, but if I took my hand off the lens and moved it to the body, autofocus would reliably unlock. Then I found that if I held the camera with my left hand in contact with both the lens and the body (as shown in the attached pic), the camera simply would refuse to autofocus. That would happen with all my lenses, even my primes.
I've told Nikon about this, hoping to hear that they've seen this problem before and know how to deal with it. In my own estimation it looks like a grounding problem.So far, no answer. I'm almost reluctant to pay to ship the body back a third time since Nikon seems unable to deal with the problem.
Russ, I'm sorry to say I've never encountered this problem, or no anyone else who has. Are the zoom lenses loose in the mount? Do all your zoom lenses do the same thing with the camera? You don't list lenses in your profile, so I have no idea what lenses you have. Is this happening with Nikon zoom lenses, and non-Nikon lenses? What about prime lenses? Does it happen with primes at all?
Hi Ned, Yep, it happens with all my lenses: Nikon 16-35mm f/4, Nikon 70-200mm f/4, Nikon 24-70mm f/2.8, Nikon 28-300mm f/3.5-5.6, Nikon 24-120mm f/4, Nikon 70-300mm f/4.5-5/6, Nikon 85mm f/1.8 prime, Nikon 50mm f/1.4 prime. On my D800 none of this happens, so it's obviously not a lens problem. No, all the lenses are tight in the mount. It's got to be an electrical problem of some sort.
I would agree with that new contact set... When I first used the 105mm VR Micro I had some of those AF lock up (it's the heaviest lens I have, using smaller primes). After scratching a bit my head, I saw that it wasn't tight enough as I could rotate it a few mm with my hand on it. Apart from rotation, it was tight in all the other directions. So when I had AF lock, I rotated the lens by a smudge and all worked perfectly, pointing to a contact alignment problem with this lens. For other reasons, I had a change of mount, contacts, and AF module in this camera, and since never had that problem again...
Are you sure that your hand is not in contact with the lens release button on the camera body. That will cause that AF to lock up.Looking at the photo your left hand is very close the button and it doesn't take much pressure to slightly compress it. Just a thought.
It's a good point, Pete, but remember, even when I don't have my hand in contact with both the body and the lens barrel -- i.e., on the zoom ring -- autofocus occasionally locks up. Also, I can put my hand in the same position on the D800 with no problem. I do that routinely when I brace the camera on my left shoulder. Also, what I haven't mentioned is that I've had the D3 since January 2008, shortly after it came out. Never had a problem until last year.
In any case the D3 went winging its way back to Nikon this morning. Before I sent it off I had a fairly extended chat with one of the techs there, who entered notes on our discussion into the case file. I'm quite sure the camera will get a thorough examination this time.
Got the camera back yesterday. Looks as if the third time was the charm. This time they replaced several parts and the problem seems to be solved. Nikon always does the right thing, after trying everything else first.
Hi Peter, Yes, you're quite right. But in the photo here I was just demonstrating where my left hand is positioned when I'd reliably get a failure. For the real thing I normally either brace both elbows against my body or swing the camera around so that it's partially supported by my left shoulder -- an idea I got from reading one of Joe McNally's books: "The Hot Shoe Diaries." Works quite well.