It is not possible to midify an SMC or SMC-M lens to behave like an
SMC-A. The reason is that the former ones have a logarithmic aperture
coupling and the latter a linear one. The *ist D requires linear, so
even if you modify the lens mount to simulate the presence of the SMC-A
contacts, the aperture will not operate properly. Furthermore, such a
modification would simulate an SMC-A lens set to a numeric aperture, and
the *ist D requires as minimum and SMC-A lens set to "A".
Cheers, Boz
Well, it was a good idea, wasn't it? <grin>
Boris
