K10D + Cosinon 50mm f/1.8, M42 extension tubes.
I use M42 lenses all the time - they've provided me with many of my favourite photos this year.
Originally posted by Nesster Pentax is unique among the remaining camera manufacturers to maintain such a level of backward compatibility to the Golden Age of open source lens mounts. So let's mount them M42's and show off the results!
The M42 Crew.
This isn't really true. I consider the Canon EF mount much better suited (mechanically) for M42 lenses, simply because infinity focus can be achieved while using a sensible (flanged) adaptor; unlike Pentax which requires the inconvenient and fiddly in-mount type. I have one, but I don't like having to use it.
But this isn't usually a problem for me, as most of my M42 shots use extension tubes, so the extra 1mm doesn't matter.