Originally posted by jatrax Imagine the complaints in 1975 when K-mount was introduced and the M42 went away.
Not really. Pentax M42 lens sales were flat then. Everyone fully expected a bayonet mount system overhaul from Pentax, and in fact were like, "What the heck is taking them so long??" The release of the K mount also breathed a lot of life into smaller camera makers who wound up adopting it as their own mount -- including Ricoh.
It had taken Pentax a long time to finally settle on a bayonet mount, but the one they went with was well designed with a good future.