The camera rotation can be changed by using the '7' and '9' keys on the numeric keypad.  The camera pitch can be changed by using the '0' and '2' keys on the numeric keypad.  The camera zoom can be changed using the '+' and '-' on the numeric keypad.  Press the 'End' key to change the camera back to the default angle.  As the camera rotation or angle changes, notice the position of the white rectangular box in the minimap.  This white box represents the current screen and camera angle.