One of the unfortunate side-effects with the intro-DSLRs is they they are not 100% "framed" in the viewfinder. The only SONY camera that is ... is the A900. Even the A700 has only 95% of the image the camera's sensor sees framed viewable in the viewfinder.
Framing Differences
Framing-differences.jpg
You see even less of the real framed view with the
A2x0-
A3x0 series of DSLRs.