Originally posted by Ishpuini I have no experience with electronic shutter. Can anyone explain how this works? Is it either electronic or mechanic shutter throughout the entire range of shutter speeds? If so, what would be the reasons to keep the mechanic shutter? Or does the electronic shutter only engage for speeds faster than 1/8000s? The documentation isn't very clear.
I know I could test myself (is it easy to deduce from the camera sound?), but I won't have the time to do the upgrade anytime soon, and I'm curious...
The selection is either
Electronic Shutter or
Mechanical Shutter, there's no overlap.
Electronic shutters work by reading the pixels individually during the exposure, so there's a noticeable delay (fractions of a second, but noticeable) between the start of the exposure and the end of the exposure, even though each pixel is only exposed for the chosen time, hence the weird smearing effect you see on a lot of aeroplane propellors in recent videos.
With a mechanical shutter, all the pixels are exposed at the same instant, then the reading is performed subsequently, so, as in the previous example, aeroplane propellors are either depicted as individual clearly defined blades or as a blurred disc, depending on the speed of rotation and the shutter speed.
It's mostly a case of "nothing to worry about" unless you have a specific reason to want a very high shutter speed. One example Pentax quotes (somewhere) is the use of wide-aperture lenses in bright light to emphasise image separation (minimal depth of field) … a function many of us have used ND filters for in the past
When engaged in LiveView, the Electronic Shutter makes the camera virtually silent (just the sound of the aperture in auto exposure) and eliminates the risk of blur induced by mirror or shutter activation, but see comments regarding Horizon Correction and 2sec Timer above.