It's 12MP cropped (exact same as the A700). Don't use it. It's just limiting yourself. Just take the big picture and crop as needed.
Canon 7D - 5D | 550EX - 430EX II - (2) PW FlexTT5 | 24-105 f4L | 70-200 f2.8L IS | 100 f2.8L IS | 50 f1.8 II