[iamarunr]

I got this lens, Kimunor 500mm F8.0, from a friend who isn't using it anymore. I thought I would play with it with my K-x. It's a K-mount adapter but it's not rigidly fixed lens, is there a specific position that I need to align it with.

Also apart from the Zoom and Aperture ring, it also has another adjustment below that that reads C with a double way arrow, not sure what's it for. Can anyone help me with this.

Appreciate your help.

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Last edited by iamarunr; 05-21-2011 at 02:28 PM. Reason: Kimunor 500mm f8.0

[Adam]

A photo would probably help us answer the latter, but didn't you mean focusing ring instead of zoom ring?

[iamarunr]

Here's the picture that I found on Flickr.
All sizes | My new 500mm $20 lens | Flickr - Photo Sharing!

Right below the ring marked with 32, 22, 1, there's another ring that says (0<-------->C).

Thanks.

[burnt umber]

The O-C ring allows you to step down the aperture once focusing is done. Set the aperture to 22 and then rotate the O-C ring to O which means Open. The aperture blades open back to the f/8 position. This allows focusing while not dimming the image as smaller apertures. Once focused move the ting back to C and the blades close back to f/22.

The lens is slow but relatively crisp for a lens that only has 2 elements.

[bratt]

I am just guessing but I would bet it is a preset mechanism. Like on the oldest Takumars, set the desired aperture on the numbered ring. Then slide the Open - Close switch to focus then stop down.

[Douglas_of_Sweden]

O = Open
C = Close
Like bratt said.