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09-22-2012, 03:50 AM   #1
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Join Date: Sep 2010
Location: Kuala Lumpur, Malaysia
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Vivitar Wide Angle MC 28mm f2.8 disassembly - Need help identifying a part..

I recently got this lens off somebody. Had the dreaded Ricoh pin, so I disassembled the mount to remove the pin from the inside.

2 things happened:

1. The aperture ring somehow got dislodged a bit - enough the send a small bearing ball flying into the depths of my room. I gave up trying to look for it, maybe it'll pop up sometime when I decide to clean my room. Anyway, now I have a stepless aperture ring

2. A small bronze coloured part fell off, but I couldn't identify where it came from :

Hope that somebody who has experience disassembling this lens could help me identify where this part is supposed to be. Here are the pictures for the inside of the metal lens mount:

And the inside of the lens (from the rear):

I'm suspecting that it has something to do with the 'A' setting, since the 'A' setting of the lens doesn't register in my K-5 (I didn't try the lens on my K-5 before disassembly, so I'm not sure if it was working in the first place).

Side note : I tried to salvage a metal bearing from my Pentax-M 28mm (which has haze and lens coating problems). Turns out that the bearing for the aperture stops is larger than the one from the Vivitar which flew off.

Then, I dropped a screw from the's gone as well (for now).


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aperture, k-5, k-mount, lens, mc 28mm f2.8, metal, mount, pentax lens, pin, slr lens, vivitar
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