K100D SR is Locked when Off

hcoley said:

I can imagine that it is locked because some permanet magnets hold
it in place when power is off and when power is on the
electrmagnetic coils are what counteracts the permanent magnets [...]

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Good analysis, and after looking at the SR mechanism diagrams again I am sure that SR uses magnetic not mechanical lock. (The rest of the story remains the same.)

This is how the whole thing probably works: sensor sits in a magnetic well formed by permanent magnets, while electromagnets just pull the sensor out of that well.

In fact, one interesting advantage of magnetic vs. mechanical lock: once SR disengages CCD plate goes to a centered "parking" position by itself (instead of being recentered by electromagnets every time before mechanical lock engages).

The bottom line is: SR is an excellent piece of engineering, simple, reliable, durable, power efficient and could last practically forever -- nice job Pentax!

-= Ivan =-

Does Pentax provide an expected life rating for the shutter and the camera in general? Just curious. Don't bother if the information is not available or not meant for public discussion.

Thanks
Teja

JohnCPentax said:

However, Pentax engineers have thoroughly tested the system,
working with the CCD manufacturer, to assure that this system will
not be damaged or cause extra wear during the life of the camera.
--
John C.

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There is not an official number for the K100D that I can state (I do know what it is), but I can tell you that it is pretty darn good.
--
John C.

pjv said:

Still need to know what was moving around in the review though.
Perhaps the permanent magnet isn't strong enough for the shaking
they were doing at the time?

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Camera orientation sensors can make an audible rattling sound if you shake the camera - this is not a major reliability concern. They have to be 'loose' to do their job.

RP

The motion sensors (officially called angular velocity sensors) are to small to create the movement when the K100D is turned off (I have a disassembled K100D at my desk). Please read my posts in this thread for an explanation.
--
John C.