Originally posted by boydmain Basically, I cannot seem to screw these lenses in far enough to "set" into the adapter, and when they are screwed as tight as I am comfortable, the aperture ring cannot be moved because I believe there is an aperture level protruding from the rear of the lens that is butting up against the inside of the camera body.
Troubleshooting:
Used two different (2nd party) adapter rings - no good
Used K-mount film and digital SLRs - no good
Used pre-SMC takumars in the same bodies - these lenses fit in and work just fine. They don't have aperture levers.
Used M42 mount bodies - the lenses in question work perfectly in them
So - am I missing something obvious I should be doing, or can I really not use these beautiful lenses on my k-mount bodies?
Please help!
YES they do work well on all K mount bodies
I have never come across a problem with the aperture pin butting up against anything in any Pentax K mount camera body when using a M42 adapter so I don't think that is anything to do with your problem.
Lets start with the basics of using a M42 adapter to cover all bases.
Lens:
Do not fit adapter to the lens.
On any lens that has the Auto/Manual switch for aperture it must be set to the Manual setting. Look through lens & confirm aperture opens/closes when you move aperture ring. If aperture is opening/closing, that's all there is for setting the lens & it is ready for use with M42 adapter.
M42 adapter:
Being a aftermarket adapter should not cause any problems as the distance lens is set back into camera body is determined by the base (flange) of the M42 mount & not the adapter. The main problem with aftermarket adapters is usually the screw to attach the locking spring being too long causing problems when removing the adapter or just generally poor fit of the K mount bayonet. Neither of these issues will cause the problems you are having.
The correct way to use the adapter (either genuine Pentax or Chinese aftermarket flangeless) is to mount the adapter into the camera body first, turn & latch into place.
Now screw the lens into the camera/adapter combo. No need to go overboard with tightening lens onto camera. Just nip it up firm, try turning the focusing ring both directions & if lens does not try to unscrew from the mount that's all you need. DO NOT try to tighten lens to make aperture/focus distance scale line up at the top. It is common (especially on after market) for the scale to not line up correctly with top of camera body. It's just a minor inconsistency you learn to deal with as you get used to using it.
Now try turning the aperture ring while looking at the front of the lens & you should see it opening & closing.
You should be good to go shooting!
Some users unscrew/remove the lock spring from the adapter to overcome the adapter removal problem with aftermarket adapters, but I am not a fan of this idea as you are relying totally on friction to keep the lens attached to camera body. It is just as easy to fix the real problem (file down or replace screw) & use the adapter as it was originally designed to be used with 100% security of lens being attached. I have never had a problem with a aftermarket adapter being used as it was designed for once it has been repaired/fitted properly.