Barry,
See this article on photo.net: K mount (M) lenses on *ist DS - what's
the real story ?
http://www.photo.net/bboard/q-and-a-fetch-msg.tcl?
msg_id=00CRot&unified_p=1
For the German readers: http://www.digitalkamera.de/Tip/28/91.htm
To sum it up:
In the *istDS set Custom Setup > Using Aperture Ring to Permitted.
Set the Mode Dial to M.
Set the Aperture Ring to the desired value and focus the camera at
your object.
Press AE-L. This will stop the aperture down and set the exposure time.
Check the depth of field if you wish. Take your picture.
Bertil
