Its design is novel due to its being the first digital single-lens translucent camera (SLT), along with the Sony α33.
The translucent mirror is fixed in position so does not have to flip up to take a still image, enabling rapid continuous shots of up to 10 frames per second.
The A55 is one of the first four Sony Alpha DSLR / SLT cameras with video mode included, capable of 1080i.
The SLT design means that it is capable of using phase-detection autofocus during video recording.
The camera's body-integrated image stabilization produces heat, causing the camera to stop video recording after these recording times: SCREEN: Flip F, Front Flip F+, Articulating A