Problem with manual focus lenses

[JohnBrew]

It's been awhile since I tried to mount any manual focus lenses on my D810 (except for the 55 Otus, which is fine) and since my camera returned from being serviced by Nikon. So today my wife wanted to do a hike and just for grins I threw the 105 2.5 Ai on. Nothing but f32 comes up in the viewfinder, which this lens does not have!, and no adjustment is possible. Double-checked my non-CPU settings and everything was copacetic. Tried the Zeiss 21 ZF.2 which doesn't need a special setting and the same thing - it won't move off f22 no matter the aperture adjustment and the shutter won't fire. Moving on to the the Zeiss 50 Makro ZF - same thing - f32 which this lens is also not capable of, checked that the non-CPU data was correct and it was.
Ideas?
Should I contact Nikon?
Thanks for all replies.

[Bjørn Rørslett]

How is the behaviour of the camera with AFS lenses?

[JohnBrew]

Thanks for replying, Bjorn. AFS is fine. Zeiss Otus, a ZF.2 lens also functions with no problems. I was doing some long exposure work two days ago with both the Otus and 70-200 f4 with everything working as normal. This situation seems a bit weird to me.

[Akira]

Does the Ai coupling ring around the mount of your D810 work properly?

When you remove the lens and manipulate the Ai coupling ring directly, the aperture value and the shutter speed (in A mode) or the aperture value and the exposure indicator (in M mode) in the viewfinder should change accordingly.  My D750 working properly behaves like that.

[Bjørn Rørslett]

Does the Ai coupler ring rotate freely on the camera? It would be of no consequence to AFS lenses or even lenses with  CPU (like the ZF.2 series) *if* the latter kind is operated by dialling in the aperture from the camera not by rotating the aperture ring on the lens.

There is a coupling resistor plate connected to the Ai coupler and if your camera is like a Df, it is possible to get a hair-line crack in the ceramic plate and this will lead to the erratic behaviour you describe. Such cracks might result after an impact to the front of a mounted lens. The mirrorbox design is not likely involved here, but whether or not a ceramic plate is used instead of a electronic print certainly is significant.

A binding or jammed Ai coupler might also lead to a similar irregularity however in this case the fix is very easy for the service facility.

[JohnBrew]

OK. Thanks Bjorn and Akira. What I really find strange is how the Otus works fine and for all intents and purposes the ZF.2 21 should be no different, but refuses to work. I will make further tests tomorrow.

[Roland Vink]

For the AI 105 you need to set your camera so you can adjust the aperture via the aperture ring, not the command dial. But for your CPU manual lenses, either way should work.

[tommiejeep]

John, my almost new Df had similar problems ( Bjørn's "humongous" Df thread).   Could not use manual or D lenses on it.  Discussed with the Manager of the Nikon Service Centre but we were having a problem with communicating  .  Anyway , he knew what it was and Nikon had sent a Service Advisory to the Service Centres.  The had to replace the ceramic connection.   Under warranty and they had the part.   I am assuming that the Df had knocked against the D300s, 500 vr on the seat of my rough, diesel jeep.

Hope you get it sorted.
Tom

[David H. Hartman]

The meter coupling ridge on the lens contacts the meter coupling lever on the body. On cameras like the F3 and FE2 a thread connects to the FRE (functional resistance element) which must be the ceramic part that may be cracked.

I'd check to see that the meter coupling lever on the camera is not stuck at f/32. If it rides smoothly against the lens meter coupling ridge then it may well be that the FRE is cracked or otherwise damaged.

I'm trying to figure out how the FRE could be damaged by an impact. Something must be substantially different in the implementation on modern cameras.

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I've never set my cameras to control the aperture with the aperture control ring. Lenses with a CPU have the aperture set by the subcommand dial. Manual focus lenses are all set with the aperture control ring as none of mine have CPU(s). This works seamlessly for me.

I think I adopted this strategy in the first week of F5 ownership and continue this to today with my D800.

___

Short version: send the camera to Nikon.

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I hope I got all the terms right.

I hope I haven't stuck my foot in my mouth too many time here.

[Bjørn Rørslett]

For the record, it is the implementation of the FRE on a ceramic substrate that causes the issue on modern cameras. This lacks the pliability of the older print approach. Thus, while it might provide much smoother operation (and functionality) when intact, once it is broken it is essentially "blind" to the actual aperture setting. Or values are reported erratically if the crack is hair-line and electric contact occurs intermittently.

I do have reported this as a bug to Nikon.

[JohnBrew]

Thoroughly checked everything mentioned this morning. All levers on the outside and inside of the mirror box move freely. I cannot find any cracks anywhere. However, David may have hit on something because the camera shows f32 without a lens mounted! And moving the two levers would do nothing which would make that value change.

[JohnBrew]

Is there any chance that in replacing the shutter, Nikon might have fouled up something else?
Grasping at straws here.

[Bjørn Rørslett]

You won't able to see any cracks because the ceramic plate is inside of the front shroud.

[Erik Lund]

The Aperture tap on the camera mount must move freely and return to it's normal position indicated by the red circle, otherwise the camera won't show/know the correct aperture value set on the lens.

[JohnBrew]

Thanks, Erik. Yes, that lever moves freely and returns correctly. It has a quite strong spring action. I tend to think of this as a camera problem as having the problem show up on three separate lenses would be rare. I will call Nikon service Monday morning.