Mirror height is about the same in the *ist-D[x] series, width changes with the Ds to the APS format. I'd get an old A body I didn't care much about to experiment with.
Cory Papenfuss wrote: >> 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! >> >> > Registration distance will definately be a problem for this > exercise if you want to try to maintain infinity focus. Last time I > handled an FD lens, the breech-lock seemed "smaller" in diameter to the > K-mount flange... Maybe it could be made to fit *inside* the K-mount body > by 3mm? Of course mirror clearance is a big problem, but maybe for the > smaller mirrors of the APS-DSLRs it's OK? > > -Cory > > -- > > ************************************************************************* > * Cory Papenfuss, Ph.D., PPSEL-IA * > * Electrical Engineering * > * Virginia Polytechnic Institute and State University * > ************************************************************************* > > > -- -- 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
