Originally posted by bossa Is it some kind of electronic shutter like a LCD blind over the AA filter or something?
Easy.
The K-01 has a new 1/4000s shutter which the PR says is quieter. Moreover, it is open by default (like on a NEX) so activating LV doesn't have to activate the shutter every time you want to compose an image (w/o taking one). This would tear down the shutter quickly. So, shutter open by default, which is good for the shutter and the shooter, but bad for dirt during a lens change.
The time you push the trigger, the first curtain closes, the exposure begins, the first curtain opens, the second curtain closes, exposure stops, and second curtain rewinds to the default open position. In a normal shutter, both curtains would have to rewind after an exposure taken.