I'm researching different cameras and I've come across a question that I can't find a straight answer to. How do shutters in digital cameras work from a photographer's perspective?
Firstly, does a mechanical shutter in a digital camera work the same way as in a film-based camera? If I use a slow shutter speed, am I actually exposing the sensor for a prolonged period of time or is this more like capturing a video and then layering the frames on top of each other?
Secondly, do mechanical shutters provide a global shutter for CMOS sensors or does one still get a rolling shutter effect? Again, what about very slow or very fast shutter speeds?
Finally, what do electronic/digital shutters actually do? Again, am I actually varying the exposure time of the sensor (i.e. the length of time for which charge can accumulate before the camera reads out the image)? What advantages does a mechanical shutter have over a digital shutter? Is the continued exposure of the sensor during readout going to cause problems with fast shutter speeds?