The third party lenses should be more easily modified since they were essentially the same designs from the mounts forward in most cases.
Cotty wrote: > On 10/2/07, Collin R Brendemuehl, discombobulated, unleashed: > > >> I'm about to propose a heresy. >> Nothing that G K Chesterton or Cornelius Plantinga would write about, >> but heresy never the less. >> >> It's come to my attention that a lot of old FD mount lenses are going >> pretty cheap. And the breech system attached to the >> outside of the body, not really internal .... soo >> Remove the mount from an old Canon body and fuse it to a screw-mount >> adapter and voila -- a Canon-> Pentax adapter. >> Then just remove the aperture coupling from the lens. >> >> Next time I find an old FD body and lens that's worthless, I may give >> it a try. (I just saw an old Canon 300/4.5 going >> for a modest price and this idea entered my mind ...) >> >> Yes, it is heresy. But can I be cleansed? Somebody help me ... I've fallen. >> (Or is this a heresy/project better suited to Cotty?) >> > > I'm here. > > Pentax K register distance is 45.46mm > Canon FD register distance is 42mm > > This means that to alter an FD lens to fit a K mount camera (without > using an adapter containing an optical element to correct for infinity > focus) you would have to remove over 3 and a half mil from the back of > the FD lens flange. If you're going to use a 42mm threaded adapter, then > add the thickness of the adapter to that. Might be problems in that > there's not enough room on the back of the FD lens before problems start > in terms of aperture ring etc. You may or may not have problems with the > rear element of the lens not clearing the mirror. I don't have an FD to > look at, but where there's a will, there's a way. > > I have some links on the bottom of this page that might be of further > interest: > > <http://www.cottysnaps.com/snaps/mods/details.html> > > It's a big job but as an engineering exercise, viable, if expensive. Of > course, as a hobbyist, cost is not justifiable so go to it! > > > > > > -- -- The more I know of men, the more I like my dog. -- Anne Louise Germaine de Stael -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
