Nikon D7000 thinks aperture of non-cpu lens is always 16 and overexposes photos

Question

I have a non-cpu lens with manual aperture control (I use the aperture ring to set it, and it stays that way when I shoot). My D7000 used to work fine with this lens in A mode - all images were exposed correctly. Manual lens settings were 58mm, f/2, and the camera used to always show f/2 as the aperture setting in mode A.

Recently it started behaving strangely: the camera thinks that the aperture is always set to 16 (with the same manual lens settings), even though it's impossible to set the aperture for non-cpu lenses to non-default value, and it overexposes all images. If I try to change the maximum aperture to 16 in manual lens settings, then it thinks that the aperture is always 90. Help, anyone? Is my camera broken?

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Upd: I have no idea what I did (I just removed the lens and put back on several times), but now it's stuck at 11

Could you specify the lens you're using? From the description, it sounds like a Helios 44M. — Blrfl, Jan 04 '15 at 17:00
No idea if it'll help, but dpreview has a thread on a similar problem with a D700. — inkista, Jan 04 '15 at 17:57
@Blrfl, yes it is a Helios 44M6, but the problem's the same for all non-cpu lenses that I've tried. My camera used to work perfectly with all of them. — Grisha S, Jan 04 '15 at 20:56
One more clarification: Do all of the lenses have anything in common like an adapter, or are they a mix of F-mount and others? (Trying not to jump to the conclusion that it's the body.) — Blrfl, Jan 05 '15 at 03:37
Sorry, more questions... Is the meter-coupling lever (outside/above the mount) engaging with the lens, or does it stick? (In the answer by Michael Clark, in the 1st picture, at the 1 o'clock position) How does it behave when the lens is off. the camera on, and the lever moved manually. — user1941371, Apr 03 '16 at 20:52

Euri Pinhollow · Accepted Answer · 2018-07-31T08:40:42.433

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Have you checked the mechanical linkage on the body that reads the aperture setting from objective to see if it is stuck? If it is not stuck try moving it by hand and see if the aperture reading changes.

The mechanical aperture ring likage may be used to read the aperture ring position and if it is not in the pictured position and springed and moving around fluently camera may misread the aperture.

This coupling is absent on cheaper models like D40, D5000, D3300, etc.

edited Jul 31 '18 at 08:40

answered Apr 04 '16 at 11:02

Euri Pinhollow

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The tab highlighted in the picture doesn't control the aperture. But as you mention, the Ai tab does read the aperture's position. – scottbb Jul 13 '18 at 16:33
@scottbb it's on camera and camera is deciding the aperture, that's what I meant. Feel free to edit to clarify that with edit if you find it potentially confusing. – Euri Pinhollow Jul 14 '18 at 10:46

score 2 · Answer 2 · answered Jan 05 '15 at 04:19

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Have you checked the mechanical linkage on the body that controls aperture to see if it is bent? It is the tab on the left just inside the lens flange. even if the camera is not controlling the aperture, it may still attempt to use this linkage to estimate the position of the aperture set by the dial on the lens.

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Here's a closeup. the aperture control link is where the blue arrow is pointing.

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answered Jan 05 '15 at 04:19

Michael C

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No, not bent, looks perfect – Grisha S Jan 05 '15 at 07:38

Nikon D7000 thinks aperture of non-cpu lens is always 16 and overexposes photos

2 Answers2

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