On Wed, 20 Nov 2002 21:00:14 GMT, Andrew wrote:

[...]
>Being an Ai lens, mechanically
>it was excellent. Build quality went noticeably downhill ever since
>the Ai-S series arrived.
>Andrew

?????????????
I would say, "after the AIS series"... The AIS MF
were the best-made of all (except for the "E"
versions), and tend to have the smoothest focus
with the least wear problems (two adjustable
hold-back pins are used in the focus-mechanism,
instead of one as in the AI lenses, helping to
keep things better-centered during focus, and
more easily adjusted after helical wear). The
aperture mechanism of the AIS lenses is also
improved, permitting use of the actuator lever
by the camera to adjust the stop in auto modes
with reasonable precision. I can think of no way
in which the AI lenses were preferable (and with
a few FLs, the optics were improved in the AIS
versions) - though they are often functionally
the same...