Is your image size in camera set correctly?
You can also have the APS-C capture option set to on (or auto and be shooting with a lens meant for a crop sensor). That will give you the 4800x3200 resolution too apparently.
its set at 15.0 m..highest setting listed...where is the APC-capture option listed? somewhere in the menu? I have a Sony 10-18mm and a Sony 50mm 1.8..also a 55-210mm...these are all for full frame Sony's no? thanks for your input