The ideal bayonet mount for sealing and resistance to wear is the external bayonet as used in the Exacta, where the flanges are outside the lens throat and pull the lens back on to the flange, without contact between lens mount and flange while it is being turned. I think the difficulty in providing a mount which could accept both screw and bayonet fittings is not insuperable (Miranda did it with one of their cameras in the late '60's), but I recall there was an issue with the diameter of the mount, although memory now fails me as to exactly what it was! I recall having a sinking feeling when the change was made that my then much smaller collection of lenses would be worthless, but it hasn't happened even yet. And then, a few years later, I bought my first ME and started on the merry path of collecting bayonet mount lenses, having sold my screw-mounts to a friend - no problems! The thing to recall is that, for years, Pentax had been heavily criticised in all the photo magazines for sticking with the screw-mount technique, when everyone else was extolling the virtues of bayonet mount. Just like last year, when members of this group were moaning that Pentax have left it too late to produce a serious digital! Then they did it, and had a runaway success with some very very good cameras, right up to the M-series. I'm happy to stay with Pentax - I expect my *ist-D's to last me a good ten years - in fact they'll maybe see me out...
John Coyle Brisbane, Australia ----- Original Message ----- From: "John Francis" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Sunday, September 05, 2004 12:14 PM Subject: Re: REV: *istD: to wait or not to wait that is the question > > Fortunately there wasn't an internet at the time, so we weren't > deluged with complaints that the M42/K-mount adapter was 'crippled' > because it didn't provide full-aperture metering. > > After all, it wouldn't have been *that* difficult to come up with > a mechanical coupling from the K-mount actuator lever to the pin > on the back of an M-42 lens, would it? > > Shel Belinkoff mused: > > > > But Paul, there was always that little adapter that allowed screw mount > > lenses to be used on the K bodies. Surely Pentax could have made that > > available with an earlier switch to bayonet mounted lenses. They could > > have been loyal to current users and met the competition head on. > > > > Shel > > > > > > > [Original Message] > > > From: Paul Stenquist <[EMAIL PROTECTED]> > > > > > > Just imagine if Pentax had made a bayonet mount Spotmatic in, like > > > > 1968, and concentrated on making an innovative pro-level body back > > > > then, instead of coasting the way they did... > > > > > > > > > > > > > > True Frank, but there were two sides to that story. Those of us who > > > were using screwmount in the seventies were none too happy to see > > > Pentax obsolete our lenses. I think the company was torn between being > > > loyal to their user body and meeting the competition. > > > > >
