Archived posting to the Leica Users Group, 2007/04/25
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]On SLRs AF works at full aperture. It cannot compensate for focus shift when the lens is stopped down to working aperture. The Contax AX uses the moving film plane to focus the lens wide open, not to compensate for focus shift when stopped down.. On RF cameras, if the AF is designed to work through the lens at working aperture, the lens' DOF will compromise AF accuracy. This is why the G2 and many P&S cameras used an external AF system. The only way to compensate for focus shift when the lens is stopped down is if the AF sysem is supported by a look-up table built into the camera with data for each lens. ----- Original Message ----- From: "Lawrence Zeitlin" <lrzeitlin@optonline.net> To: <lug@leica-users.org> Sent: Tuesday, 24 April, 2007 11:55 PM Subject: [Leica] Re: Nocti focus shift SNIP > Isn't this a good rationale for incorporating autofocus in the next > iteration of the digital M camera? It could be accomplished by moving the > sensor a millimeter or so after the lens was set to approximate focus. > The old Contax SLR did it. Why not Leica. This would permit use of all > Leica lenses. Of course you could turn it off it you truly wanted the > eyes out of focus. Of course I don't have a Noctilux so the problem is > just academic for me. > > Larry Z > >