Originally posted by Gimbal Usually when the mirror is up, the shutter is also up, and thus the sensor plate is held in position by the SR-system motors. But maybe the mirror also makes some sound? I don't know.
I wasn't trying to revive that explanation, I was just pointing out that the quoted thread ends up in a rather ambiguous way.
I played more with my cameras, and your explanation matches the behavior I observed. I am surprised by the implications.
It sounds like the sensor plate is lying around all the time and only gets moved into place at the time the exposure is made or the mirror is lifted for cleanup. I'm surprised the camera can move the sensor and stabilize it so quickly.
I am also wondering about the succession of actions - the camera must try to figure out if the shake can be compensated to show the indicator, and then it must place the sensor into position and actually counter the shake when the shutter is fully pressed. Pretty amazing they can do this in a fraction of a second.
Still mysterious why the sound is better muffled on some cameras.