D7100 problem with 300f4 AFS

<p>Can anyone help me diagnose this problem?<br>

<br />I've purchased a D7100/18-140VR ki and today began setting up the camera. Everything was perfect for most of today. I had begun running through AF fine tune on the lenses I plan to use with this body. The third was my Nikon 300f4 AFS. Having tested from -20 to +20, I then put on my TC1.7EII. At this point the camera and lens stopped autofocusing. No AF movement of any kind whatsoever. Since then the body has completely lost AF with the 300f4 AFS with or without the teleconverter. The body still autofocuses normally with the 18-140 AFS. I have two other bodies here, a D700 and a D5100 (this latter does not have a built-in focus motor). Both these other bodies autofocus perfectly with the 300f4 AFS. I have tried changing all settings on the lens (A/M or M, Full or focus limited, aperture ring. I have tried a variety of AF settings on the body. I have done a body reset. B & H technical support cannot work out the problem.</p>

<p>I don't want to return this camera just because of some minor setting problem that I could easily correct if I could work out what it is, especially because I will have wasted most of today checking for hot pixels, sensor dirt etc, but I will have to pack up this camera and lens for return if I can't correct this.</p>

<p>Anyone recognize the problem or otherwise have insight?<br>

thanks</p>

 

<p>What was the f stop when the 1.7 TC was mounted? If it was f8 or wider then try it with a Nikon 1.4TC to see if that corrects the problem.</p>

<p>There should be a message on LCD telling you what's wrong.</p>

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<p>There should be a message on LCD telling you what's wrong.</p>

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<p>I did not have the LCD on at the time. I'll try that though - any specific advice?</p>

<p>thanks</p>

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<p>What was the f stop when the 1.7 TC was mounted? If it was f8 or wider then try it with a Nikon 1.4TC to see if that corrects the problem.</p>

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<p>It was wide open (=7.1) since I was AF fine-tuning. But the camera no longer focuses the lens itself, without the TC.</p>

<p>Does it work if you don't fiddle with AF fine tune?</p>

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<p>Does it work if you don't fiddle with AF fine tune?</p>

 

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<p>Good idea, but since I did a camera reset, AF fine tune is now off. Also, it is not a problem acquiring focus; it is that there is no AF activity whatsoever</p>

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<p>There should be a message on LCD telling you what's wrong.</p>

 

 

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<p>No error messages on the back when I press either of the info buttons. Was there anything you were expecting?</p>

 

 

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<p>No error messages on the back when I press either of the info buttons. Was there anything you were expecting?<br>

Yeah, 'unable to communicate with lens, please clean the copper contacts' or something.</p>

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<p>no, no error messages on LCD. Aperture is communicating fine.</p>

<p>So, just to summarize, the 300mm AFS lens works with other bodies and the D7100 body works with other lenses. It's just that specific combo that doesn't move?</p>

<p>When it's a <em>unique</em> paring problem, I'd go for a comms-pins 'alignment' problem. I reckon the physical fitting of the TC has moved/shunted/misaligned something.</p>

<p>If you unlock the aperture and, say, set f8 on the lens, do you get an error in the top LCD?</p>

<p>It almost sounds as if the focus switch on the lens is set (or rather electronically appears to be set) at <strong>M/A</strong> not <strong>M </strong>only when mounted on your D7100, I wonder if that is pin specific?</p>

<p>I'd second what Mike said, plus the test he suggested. Plus, check all pins on the lens and TC for dirt and if they're still all equal lenght/heigth/etc. It could be a case of small tolerances with the spring action of the electronic contacts, making it just miss contact on the D7100, but not on your other cameras.</p>

<p>For the record: the problem can not be the effective aperture being too small; it'll be f/6.8 which is too small according to Nikon for AF action on the previous generations of DSLRs (D700, D5100 in OP's case). But I know this combination works a bit (very error-prone) on D300 and D700 - by itself, the aperture is not a reason for no AF action at all. And more important: the D7100 should work far more reliably with a combination this slow - according to Nikon, AF with apertures as small as f/8 is OK on these models.</p>

 

<p><strong>Late EDIT!</strong>, I've mixed up the M/A or M labels. The camera is reading is as M when you've got it set at A/M, so it doesn't try to AF when it should! </p>

<p>Sorry for confusion!</p>

<p>Sounds like a software memory problem on the camera which may have to do with the fine-tune process. Since they are both Nikon products that have caused the problem, I would contact Nikon. There may be another more robust way to reset the camera that is not in the manual.</p>

<p>Update: partial cure and new dilemma<br /> I cleaned lens and camera contacts again last night, this time with isopropanol, and the AF worked!<br /> Checked again this morning and at first AF did not work, then it started working after I switched from Single-shot to Ch modes, and then back again.<br /> So it may well be dirty contacts ie not any serious problem. Now my decision is whether to exchange the camera. I'd like to keep it if possible, since the sensor was exceptionally clean and there is not even one hot pixel at ASA3200, and as I have quite limited time now before a wildlife trip for replacing the body and setting up the new one. So, new question, was this just a glitch of no importance, or is the body suspect?</p>

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<p>Checked again this morning and at first AF did not work, then it started working after I switched from Single-shot to Ch modes, and then back again.</p>

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<p>My 300 f/4 behaves this way with and without TC14EII on my D300 every now and then; it also has a bit of play when mounted. Instead on my D700 it's absolutely fine (and mounted tighter). The D300 works fine with all other lenses I have (including AF-S ones). This intermittent problem has grown a bit over time, in the beginning I never have had these problems. I cannot loose the idea that it's a matter of tolerances on the contacts, just a little bit too much space causing the AF pins to loose contact; a bit wear & tear (on the lens mainly). But, I admit, I never had Nikon take a look at it, so I just have a suspicion, nothing else.<br>

That said, I'm not convinced it is the body, it's more the combination lens and body that seems to be the issue. Given your body is brand new, I would lean towards exchanging that (clean sensors and no hot pixels are the norm - not an exception), otherwise you'd might end up sending in both.</p>

<p><em>"My 300 f/4 behaves this way with and without TC14EII on my D300 every now and then; it also has a bit of play when mounted."</em><br>

Same here with the exactly the same combinations. I am pretty certain the root cause is the amount of rotational play at the lens mount leading to bad contacts, although I also wonder about the carrying of the camera on a body-mounted strap and the possibility that the heavy lens was deforming the mount and breaking contact. I could always fix it by either switching off the camera body and twisting the lens within its "play" or by removing and re-mounting the lens. Very annoying. I now have a 300mm f/2.8 AF-S VRII and there is almost no play - and no intermittent AF failures in 2 years (but I also carry this rig by a strap attached to the lens tripod mount). I note that my "G" lenses have closer mount tolerances than the earlier lens models with aperture rings?</p>