Originally posted by bencoskater If an EVF has been implemented to the OVF, it will only work when the camera is in Live View. This would be one of the purpose of the IR presence sensor below the OVF. It will turn off the LCD screen of the camera. As the mirror is down and the photosensor unexposed, it's not possible to have an EVF outside of Live View mode.
In my opinion the new LCD display in the EVF will display the information such as speed; aperture; EV; ISO. It has been positioned in consequence of the new prism. But I am not sure because in the patent (if it's related to the new DSLR) talks about EVF and color display.
If there is any kind of more advanced evf like overlay, even if it just displays what we already have but by different means, the eye sensor makes sense for saving battery by switching it off/on.
A overlay display needs way less resolution that a proper evf because it displays only overlay information. If the fabled RGB sensor matches the overlay display resolution at say 2MP you could display useful focus peaking, blown highlights etc. The data would then be fed from the RGB sensor to the overlay display. Never from the sensor itself. For some stuff you could usefully do this with both components having pretty low resolution. The current focus point display is a sort of super low res version of this achieved by slightly different means.
Edit: just realised the Fuji X-pro 1 camera is an example wonder what resolution the overlay is for that camera.
Edit 2: I guess the overlay display actually needs quite high resolution to show nice, small and clear typography etc. The data for peaking and exposure can come from a much lower resolution sensor.