If this thread is about non M42/K so it is about my Leitz 560/6.8 I bought it with Novoflex gear and Nikon mount. I converted mount to M42 and now can use it with my K20D. I don't have infinity - it can focus up to 100-150 meters.
here is my thread
http://www.pentaxforums.com/forums/p...mpression.html