D7100 with AF-S 300/4D & AF-S 80-200/2.8D Compatibilty

[kk_hui]

<p>I encounter intermittent AF failures (AF just went dead) on my D7100 with the captioned lenses viz AF-S 300/4D (with or without TC14E) and AF-S 80-200/2.8D straight. Both lenses works flawlessly with my other bodies D200 and D800.<br /><br />My D7100 has no AF issue with my AF-S 500/4D (with or without TC14E) and other lenses including the AF-S 28/1.8G and AF-S 300/2.8D (with or without TC14E and TC20E).<br /><br />I've visually checked for lenses alignment, physical fitting and pin contacts (height) and they both appear normal. Contacts were cleaned but to no avail. All screws on both the lenses/ TCs and body mount were checked also. They are all tight and none of them are loose in anyway. I even blow clean the AF sensor located at the bottom and behind the mirror on my D7100.<br />It doesn't make a difference unfortunately. I cannot loose the idea that it's a matter of tolerances on the contacts and D7100 is less tolerable (tight spec?); just a little bit too much space causing the AF pins to loose contact. By twisting the lens within its play I can sometime get its AF to work again but not always ...<br>

Or could there be firmware bug(s) in the D7100?<br /><br />Wonder if it's an unique pairing/ compatibility problem?<br />Your experience and insight on these combos?</p>

[ShunCheung]

<p>If you are using the same TC-14E with the 300mm/f4 AF-S and 500mm/f4 AF-S, since only the TC is mounted onto the D7100, the physical mount connection between the 300mm/f4 and D7100 is no longer the issue.</p>

<p>This problem is unique to your equipment, most likely the D7100. Probably something is a bit off spec. I would get Nikon repair to take a look at it.</p>

[nick_baker]

<p>When I got my D7100 a year ago it focused only intermittently with my 300 f4AFS. Whether coincidentally or not, the problem first occurred while I was using a TC. I exchanged the D7100 body but the next one had the same issue. I did a lot of contact cleaning, examining the contacts, holding the lens firmly in place, etc. The lens worked flawlessly with other bodies (D5100, D700). The D7100 works flawlessly with other lenses. I never resolved this problem, which sounds similar to yours.</p>

[kk_hui]

<p>Thanks, Shun!<br>

Indeed the same TC14E is used with my 300/4 and 500/4. All the symptom appears to be pointing to a D7100 problem when coupled to the specific lenses viz AF-S 300/4D and AF-S 80-200/2.8D. I've not call Nikon repair yet.</p>

[ShunCheung]

<p>Just to be sure, I mounted my 300mm/f4 AF-S onto the D7100 (directly, no TC). At least my combo works perfectly with excellent AF results.</p>

[nick_baker]

<p>There now seems to be an explanation for these phenomena. Seemingly it is caused by the chip in some of the older lenses. See this discussion.<br>

http://www.dpreview.com/forums/post/56125043</p>