Sony A55 has a 16.0MP APS-C (23.5 x 15.6 mm ) sized CMOS sensor and features Bionz processor. On the other hand, Sony A65 has a 24.0MP APS-C (23.5 x 15.6 mm ) sized CMOS sensor and features Bionz processor. Sony A65's sensor provides 8MP more than Sony A55's sensor, which gives a significant advantage in real life.