Actually it's a fairly minor difference with major implications. Most pre-A lenses are adequately linear up to f8 or f11 and only become non-linear at smaller apertures.
-Adam Vic Mortelmans wrote: > Now that's interesting! > > That's must be indeed the major mechanical difference comparint both > lens types. > > Thanks for this feedback! > > Groeten, > VIc > > Adam Maas schreef: >> A lenses have a fully linear aperture actuation. > > [...] >> A fully linear aperture is necessary for the camera to >> be able to accurately set aperture in P and Tv modes. There are a few >> cameras which can do that without a linear aperture (the Chinon CP-6 and >> Nikon FA are two) but they double check and adjust exposure after the >> lens is stopped down. > -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
