Wednesday, 28 December 2016

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


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




Answer



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.


correct position of mechanical aperture ring coupling


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