Reply to thread

Message

<blockquote data-quote="Bob Blaylock" data-source="post: 500376" data-attributes="member: 16749">These pictures indicate that linkage on one of my ancient non-AI lenses.&nbsp; That linkage has been on nearly all F-mount lenses since the beginning in 1959.&nbsp; Originally, it was just to allow the aperture to remain open while viewing through the viewfinder, and to be closed down to the selected setting when the picture was actually being taken.&nbsp; The AI-S development in 1981 calibrated that linkage to have a consistent, predictable relationship to how far the aperture was stopped down, so that the camera could use it to control the aperture setting on the lens, and that is how all modern Nikon camera bodies control the lens aperture.&nbsp; &nbsp; [USER=16783]@wev[/USER], my suggestion was that with the lens not mounted to a camera, and with the aperture ring set to the smallest aperture, if it has an aperture ring, try manipulating that linkage by hand, and see if the aperture responds smoothly and consistently.&nbsp; I'm thinking now that there's a good chance you'll find that the aperture is acting “sticky”, not always closing down quickly, smoothly, or all the way, and that that is what is causing the issue described in the OP.[ATTACH]183422[/ATTACH] [ATTACH]183423[/ATTACH]</blockquote>

[QUOTE="Bob Blaylock, post: 500376, member: 16749"] These pictures indicate that linkage on one of my ancient non-AI lenses. That linkage has been on nearly all F-mount lenses since the beginning in 1959. Originally, it was just to allow the aperture to remain open while viewing through the viewfinder, and to be closed down to the selected setting when the picture was actually being taken. The AI-S development in 1981 calibrated that linkage to have a consistent, predictable relationship to how far the aperture was stopped down, so that the camera could use it to control the aperture setting on the lens, and that is how all modern Nikon camera bodies control the lens aperture. [USER=16783]@wev[/USER], my suggestion was that with the lens not mounted to a camera, and with the aperture ring set to the smallest aperture, if it has an aperture ring, try manipulating that linkage by hand, and see if the aperture responds smoothly and consistently. I'm thinking now that there's a good chance you'll find that the aperture is acting “sticky”, not always closing down quickly, smoothly, or all the way, and that that is what is causing the issue described in the OP. [ATTACH=CONFIG]183422._xfImport[/ATTACH] [ATTACH=CONFIG]183423._xfImport[/ATTACH] [/QUOTE]

Verification