Originally posted by kingtut1945bc I bought a 1,000mm S-M-C lens and at first the focus was very smooth. One day it got very stiff, almost like a grain of sand or a loose metal chip got into the focus mechanism. It sticks at different positions every time I focus the lens. Sometimes it glides smoothly; other times the whole range is stiff and everything in-between. I have been unable to find a disassembly guide online and am not comfortable going about it blindly. Could anyone tell me where to find info on taking this beast apart?
Are you focusing using both knobs or just one? I have found focusing hard to do on the K1000/8 if you only use one knob.
Here is a link to the manual for the K Series "big guns":
K Series Telephoto Lenses
If focusing is still rough using both knobs, then as previously mentioned Eric is your best bet.