Specifically with reference to mirror-less cameras...
... is the sensor receiving incoming light at all times when the lens cap is off but the power is on- in other words, is the scene rendered on the LCD or EVF as the camera is waved around before taking the shot?
Yes, in general. There are some modes on some cameras that restrict that, and the live view lags reality a bit, but that's the idea.
on my sony a74 i can turn the rear lcd panel "in" and have evf turned on so it only turns on when you raise the camera to your eye. i prefer to have my evf
permanently turned on. an have a dedicated button set to switch between evf and lcd.
What do you mean by live view? Typically, it means that the data read from the sensor is displayed as the scene on EVF or LCD (with or without exposure simulation). Cameras have power-saving standby modes for displays, so the live view can be off while the camera is still turned on (and not in sleep mode). The camera may still be reading the sensor even when the live view is off (metering).
That's what I meant.
Understood, thank you.
Certainly Donald:
Since "Exposure is the amount of light that struck the sensor per unit area while the shutter was open" ...
... and since the shutter is always open during live view ...
... that's a lot of light !!
Beginners, please ignore the above quoted definition of exposure wherever y'all see it.
Live view is essentially video mode (60 or 120FPS typically). We have been discussing exposure in still photography.
I didn't know that. (I don't shoot video at all).
As have I.
I know lots of experienced photographers who don't understand how electronic shutters work, and complain when they don't give them the results they expect.
I don't doubt that at all but the beginners I have dealt with have no difficulty understanding the concept/function behind an electronic shutter when related to a mechanical shutter and so have no problem understanding the definition:
exposure - amount of light that struck the sensor per unit area while the shutter was open.
no comment
No problem 😊