I've been thinking about exactly what K/M lenses are capable of, and a few asides.
First off, you can do at least Program mode with K/M lenses. In fact I own a camera that offers this with K lenses(Chinon CP-6 Dual Program) and another that does this with the functionally identical Nikon AI lenses (Nikon FA). Shutter Priority is also possible if you are willing to override shutter speed selection in some cases (the Nikon FA does this with AI and earlier lenses) in both cases the camera double checks the metering after stopping the lens down, the FA will override shutter speed selection by up to a stop in either direction to compensate for non-linear apertures, this only occurs at small apertures though. An interesting capability of the CP-6 is you can limit the smallest aperture the camera will select in program mode with the aperture ring, the FA requires aperture to be set to minimum to work in P and S modes. So Pentax has never chosen to take full advantage of the automation that is technically possible with K/M lenses, even if they weren't designed with this in mind. Nikon has never produced an AF body that fully couples with AI-S lenses, the F4 is the only one to fully couple with AI lenses. In fact Nikon only ever made one camera that takes full advantage of the AI-S mount, the FA. And Nikon is the only other maker with reasonable backwards compatibility with its SLR mount, but it hasn't fully supported it's MF mount since 1989 (when the FA was discontinued). -Adam -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
