Zenitar 16mm on K3 - aperture ring pin?

[Sam Stinson]

Hi - I recently picked up a Zenitar 16mm ostensibly to shoot on a 35mm film camera but I’d also like to use it on my K3. There is a pin that engages the aperture ring and if it’s not depressed then the lens stays wide open. I think I can disassemble the lens and solve this and I’ve seen some other forum threads elsewhere that describe the process but what I’ve found is old info and none of the photos load. If someone has some details on this mod then I’d appreciate it. Attaching a couple of photos to show the issue.

Thanks and happy shooting.

[Ruben Arce]

You can remove the back of the lens and block the mechanism so the lens can be controlled manually, but that may affect the collimation. I used to have that lens and I just applied a drop of crazy glue around the pin, kept it pushed for a minute and it stayed there. It worked fine without having to disassemble the lens.

[Sam Stinson]

Thanks Ruben - I actually found someone on a Discord channel I’m on that had taken one apart to remove the pin that walked me through it - it’s very easy ! There are 3 screws to remove the M42 thread mount part, and then two screws to remove the pin mechanism. It all comes comes out very cleanly and neatly and then the aperture ring works normally. Can’t reassemble the lens incorrectly either as the M42 mount only aligns one way. Now it works perfectly on my K3.