Pentax has a history of some bad decisions regarding mounts & changes. First they chose a dreadfully small proprietary M37 screw mount which they had to abandon in only 4 years leaving all the purchasers of the early bodies out to dry. 1957
But at least they made a good decision regarding the switch to the M42 mount which had better compatibility with other brands and also offered better optical possibilities due to the larger mount size. Then they made three more good decisions regarding M42. A. They added semi-auto diaphragm, then B. Fully-auto diaphragm, and C. Fully Auto Diaphragm with the aperture sensing cam (advanced M42). All three of these changes permitted higher functionality with newer bodies while allowing the older bodies to be used as always without any loss of their original functionality. Then came another BAD decision in 1975. The switch from the advanced M42 mount to the K mount. I call this a BAD decision because the first K mount offered nothing new in terms of functionality vs. the advanced M42 other than the mounting technique and a very slightly larger lens throat. The cost was no more new M42 lenses for those who already purchased the advanced M42 bodies and even worse, the crippling of the auto-aperture and aperture sensing of the advanced M42 lenses when mounted on the new K bodies via an adapter. In one fell swoop the loyal purchasers of both Pentax bodies and lenses got screwed in the name of a different mounting technique which is in itself a very minor improvement. Not worth the price paid in incompatibility IMHO. Then came the KA lenses in 1983. This was a good change in that it didn't affect functionality of old K lenses or K bodies. Ditto for the KAF. But the advent of expensive new K bodies and K lenses incompatible with ALL K lenses & Bodies ever made is another BAD decision in terms of customer support. It is totally unnecessary and deplorable because once again similar to the switch to K in 1975, nothing is gained by it, actually even worse because at least in 1975 there was the minor improvement of the mounting technique, this time there is NO improvement whatsoever, just a LOSS of functionality. I honestly cant believe they have the nerve to release a $1000 plus D-SLR that doesn't fully support EVERY K mount lens ever made. All their top line film cameras have that and at much lower cost. I see this at nothing more than a foolish attempt to get pentax users to buy a whole new set of lenses, even though their old ones COULD BE perfectly serviceable or worse EVEN BETTER than the new ones for those who prefer the manual focus feel of the old MF lenses. For pentax to abandon all the great lenses made between 1975 and 1983 without any other gain made in the process for the customer is ludicrous. JCO
