I'm entering the world of film photography by buying a cheap Pentax K1000 and a cheap K-Mount lens. Initial research says that the K-Mounts are still in use today, but I'd like to know your opinions for future reference if/when I buy a better camera to use for a longer time. (I know very little about film camera branding/compatabilities).
What are the most popular types of lenses in use today (primarily for film cameras)? Is there one or two brands that everyone uses?