Originally posted by RioRico I now use them semi-permanently on M42 lenses that DON'T have tight focus or aperture rings. I can almost pretend those are PK lenses, as long as I don't twist them too enthusiastically (and thereby remove them from the camera unintentionally - oops).
There's a simple solution to this. Go to the closest auto parts/machine shop/hardware store and ask for a tube of * LockTite * thread sealant. There's two types: one's permanent, the other's not. Take your pick, but the non-permanent type will do just fine. A l'il dab on the M42 lens threads will keep the adapter on the lens.
Of course a l'il dab of fingernail polish or silicon sealant will accomplish the same thing.
Be sure to remove the spring on the adapter first - especially if you chose the permanent LockTite.
Now spot drill a notch at the proper spot in the base of the M42 lens for the K-mount latch pin and you've just built a bayonet mount. I off-set the notch so the aperture ring isn't hidden by the flash hood.
H2
And if anyone's tempted to trash those cheap, much maligned, don't-focus-to-infinity adapters you can send 'em to me instead. There's a way to fix that too.