Originally posted by Vanheden Big viewfinder would probably put a (little) lid on FF maniacs like myself.
Agreed - the vf size of APS-C is my main complaint. It certainly would be possible to use a mirror and finder large enough for FF with an APS sensor.
For example, the D600 FF body will show the FF view, but also show a reduced APS-C "frame" around the portion to be used when in DX mode. (It can use just a portion of the sensor when you want to use APS-C format.)
The same could have been done with the K-5 and its APS-C sensor: use the larger mirror and VF with a frameline showing the image to be recorded. This would have the advantage of showing what is just outside of the frame, like a rangefinder camera.