A digital camera could be considered as a device which digitally
samples a 2D signal. For correct sampling of consecutive
frames in time, camera capture rate should be 2 times the display
refresh rate ( ) unless there is a synchronization system
in place to activate the camera shutter when the image is stabilized
on the display (exactly between frame changes). As it is
not normally the case, if the camera capture rate is for example
Hz then the display refresh rate could not exceed 4 Hz.