OK, This is starting to make some sense. If the AS cannot cover the bandwidth of vibration frequencies fouund on a tripod mounted camera, then it would just not work if turned on. But there must me more to it than that because if they recommend turning it off, then the sensor is probably "locked down" or more stable with the AS turned off even if the vibrations are out of the working bandwidth of AS system when turned on.
P.S. The comment in the Pentax document about Pentax's "commitment to the over 24 million PENTAX PK lens legacy" makes me laugh in light of the fact they dont even bother to read the f-stop setting on most of them ( K & M series ). What a joke that is.... jco -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Digital Image Studio Sent: Sunday, January 14, 2007 7:12 AM To: Pentax-Discuss Mail List Subject: Re: Pentax DSLR Shake Reduction Question - Why turn it off on whileon tripod? On 14/01/07, J. C. O'Connell <[EMAIL PROTECTED]> wrote: > Could somebody please explain the theory why > the Pentax AS should be turned off while using > a tripod?? > > I dont understand how it could hurt, > and intutively it seems like It might help > if the tripod isnt perfectly stable due to > wind, camera mechanism vibrations, etc. It's speculative since the technical information is limited and no users to date have shared any technical test results of the Pentax SR systems response and sensitivity. The SR system is based around a set of movement detectors (gyroscopic according to link below) and an oscillating plate driven by linear motors which carries the sensor. As you would expect the system will have a limited response bandwidth which may be a due to a combination of the speed of the SR processor, movement sensors and the moving systems mass vs the motor response. We can assume that Pentax knows that the bandwidth doesn't extend into the frequency range of the vibrations caused by mirror/shutter actions or the potentially relatively fast vibrations set up by buffeting winds etc, hence their advisory. See: http://www.pentaxslr.com/files/scms_docs//PENTAX_SR_Description_091506.p df -- Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://home.swiftdsl.com.au/~distudio//publications/ Pentax user since 1986, PDMLer since 1998 -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
