Bojidar Dimitrov a écrit: ...
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".
If the A contact is insolated, you can simulate a SMC-A lens set to "A"; but not the logarithmic aperture coupling, so you do a bad exposure.
Michel