Originally posted by JPT To define a “hybrid viewfinder”, what I mean is a viewfinder with all the functionality of a traditional SLR OVF, but which can switch over to a full EVF mode at the user’s command.
You are correct that the type of hybrid viewfinder you describe would not be great.
But there is another way (in theory).
You replace the 86,000 pixel metering chip on the prism with a proper high res cheap phone sensor (shouldnt be larger).
And then (that seems to be the tricky part) you put an LCD overlay / transparent LCD display in the viewfinder image path (permanently).
This way you still have the beauty of the optical viewfinder, but you can display more detailed infos, such as blown highlights blinkies.
The small sensor would be able to track the subject across the frame if you have the computing power and algorithm.