A system and method may determine the orientation of an in-vivo imaging device relative to the earth's gravitation field. Some embodiments may enable indication of specific locations where other methods provide non-satisfactory imaging coverage. The system may include an in-vivo imaging system with a container or shell containing an orientation object. The container may be placed in at least one optical dome or optical field of an in-vivo imaging device, such as an autonomous capsule. The location of the orientation object's image on the in-vivo imaging device imager, as well as size of the image, may be determined as functions of the location of the orientation object inside the container, for each image acquired.