In a method for determining the 3D coordinates of an object a pattern (6) is projected onto the object (1) by a projector (3), the light reflected by the object (1) is captured by a camera (4), and the shots recorded by the camera (4) are evaluated. Reference marks (8) on and/or beside the object (1) are recorded by a reference camera (5). The reference camera (5) has a larger field of view (9) than the camera (4). To improve such method, the reference camera (5) is connected with the camera (4) or with a 3D sensor (2) which comprises the projector (3) and the camera (4).