BebuLamar wrote:
100% viewfinder in live view is easy and I think all of them do that. To make the reflex finder 100% accuracy the viewfinder alignment is very critical and thus more expensive to make. With less than 100% the viewfinder can show an image area to the left, right, top or bottom of the sensor as long as the viewfinder is within the area covered by the sensor is OK.
Which is why it’s a pet peeve— it’s not always convenient to switch between live view and the viewfinder. But point taken...
FWIW, the design and manufacture of mirrorless make this alignment an easier to achieve end result— but OP referenced DSLRs.....