I apologize if this has this been asked before! :^) How does the istD shutter release sound compared to the istDS/DS2? Is the istD quieter and of a lower frequency?
Dpreview.com includes a sound recording of the shutter in a full review. For the *ist-D and -DS see (or hear):
http://www.dpreview.com/reviews/pentaxistd/page4.asp http://www.dpreview.com/reviews/pentaxistds/page4.asp Hope this helps, -- Regards, Lucas

