On Tue, Feb 28, 2006 at 03:56:56PM +0000, mike wilson wrote: > > > > > From: Sylwester Pietrzyk <[EMAIL PROTECTED]> > > Date: 2006/02/28 Tue PM 03:49:23 GMT > > To: "pentax-discuss@pdml.net" <pentax-discuss@pdml.net> > > Subject: Re: Some more new camera speculation > > > > mike wilson wrote on 28.02.06 16:45: > > > > > I'm more interested in what is meant by "progressive replacement". PZ > > > contacts could be used for USM? > > Yes, they could, as in their patent (KAF3?), which I've sent in PDF file to > > a few people. > > > That would be progressive replacement, as most people seem to > agree that PZ was not a good implementation of technology.
Hmm. So if the power contacts come back, presumably we would get at least one more digital signal pin to control the in-lens features (including, but not necessarily limited to, USM motors). Additionally both the new body and the new lenses would have to include the old AF system as well, or we lose compatibility. > Replacement of mechanical aperture linkage with (effectively) > nothing is not progressive.... It depends on how you look at it. Switching to an all-electronic interface (as Canon did when they introduced the EOS mount) was progress (and means they don't have the same sort of compatibility problems mentioned above with the AF system). When DA lenses started to show up, without aperture rings, it was obvious that any future cameras would have to incorporate body-mounted aperture control. The one substantive complaint about body-centric control (it's not as precise as a mechanical system on the lens) can easily be overcome if there's a simple aperture encoder in the lens (as is done now for focal length, etc., in the FA zoom lenses).
