What field of view do the cameras have?

The DoorBird door intercoms use a hemispherical ultra-wide-angle lens (180° horizontal, 90° vertical), so that even with a minimum distance of 50 cm between the person and the door intercom, a low mounting height is sufficient. Therefore the lens is not adjustable mechanically. The camera lens should be at a height of at least 145 cm.

Please check the optimal installation height before mounting.
What kind of RFID reader is used in the A1121 series?
What is the difference between the materials V2A and V4A?