The camera in Kingdom Hearts 1 was one of the primary complaints by players. In KH1, the camera is controlled with L2 and R2 and centering the camera behind Sora was hitting both at the same time.
In KH2, they reworked the camera so the right analog stick controls the camera. This makes it much easier to control looking around, is quicker, and is much more familiar. In addition to this, clicking in the right analog stick centers the camera, and hitting R2 toggles the camera between automatic and manual control mode. So if you get annoyed with the camera auto centering, just hit R2. Overall, the camera will get mostly out of your way in KH 2. At the very least, it is a vast improvement over the first games controls.