"Matt Clara" <critics@large.com> wrote in message news:ac-dnW5oCul_pp7dRVn-jw@comcast.com...

> www.mattclara.com

> "Paul Rubin" <http://phr.cx@NOSPAM.invalid> wrote in message

> news:7xvfnihrr2.fsf@ruckus.brouhaha.com...

> > gsm@mendelson.com (Geoffrey S. Mendelson) writes:

> > > No, you cannot AIs a lens. You can scoop out the back of the lens

> > > to fool the camera, but your exposures will be off.

> > AIS only matters for the program modes of the FA, FG, F4, N2000, and

> > maybe one or two other models. I don't know if even the F5 supports

> > AIS for program mode. I don't think the 8008 supports it.

> They can't support P mode as they have no way to control the aperture. For

> that reason you can't use shutter priority mode, either.

The aperture operation may be less precise in AI vs. AIS lenses

in P and S modes, but it does work in the older cameras (at

least the FA took a quick check of the exposure as the aperture

stopped and corrected the shutter speed to compensate, as I

recall). But even in A an M modes with full-aperture metering

(as opposed to stop-down metering), the aperture is represented

by an analogue in the camera and not by the exposure as seen

through the lens with it stopped down to the actual stop

used - and this also can introduce errors (which we have come

to accept...;-).

--

David Ruether

d_ruether@hotmail.com

http://www.David-Ruether-Photography.com