Toralf, In the beginning, Pentax made screw mount lenses, then they introduced the K-Mount bayonet. Much of the lens line was converted to the K-mount. These are the K lenses, although they bear no 'K' marking.
Electronic cameras like electronic watches set the world on fire. Pentax introduced a wildly successful and compact camera called the ME along with a the mechanical MX. The older K-mount lenses were a bit big for these small cameras and Pentax introduced a new series of smaller lenses - "M". They had a common 49mm front filter size and you could carry three prime lenses for the same weight as one heavy zoom. Electronic Pentax cameras were aperture priority and Canon was pushing their shutter speed priority as great for action photography. Pentax designed the 'A' series lenses to be able to do both aperture and shutter speed priority and introduced the Super Program (Super A) and Program Plus (Program A) cameras to use the new lenses. The 'F' series of lenses were the first of the autofocus lenses by Pentax. They came out with the SF1 (SFX) camera series. The 'FA' series of lenses followed when the PZ series of cameras was introduced. They have a wee chip inside that helps determine optimal aperture to use the lens at... Regards, Bob S. Toralf asked: >>What exactly do the different letters in the Pentax lens designations mean? I've >>been looking for an explanation on the K mount info page and other places, but not >>found anything... I understand the difference between an "M" and "A" lens, of course, and I know an "FA" lens has autofocus. But how about "F"? Or "K"? And are there others?
