Even worse than the rounded corners is the fact they are set for a subject X feet away, around 3 or 6, and for further distances you have to use the outer borders and for even further distance additional distances need to be added. It is simply not a camera for really precise framing. For that you want a reflex camera with 100% viewfinder coverage, Nikon F or F2 or D3 or D4 or Hasselblad or 4x5. RF is made for quick shooting reporters who fix mistakes later in the darkroom.