Motorized dome-type cameras, also called PTZ camera, allow the creation of panoramas. These panoramas represent the whole of the scene seen by the camera. In the case of a PTZ camera and with certain constraints, the scene seen by the camera can be considered as a sphere. The creation of a panorama consists in traversing a sphere in an exhaustive way. The acquired images are then projected on unspecified support which can be a cylinder, a cube or others. The projection of the rectangular images onto a sphere inevitably involves partial overlap between images. These overlaps lead to useless calculations. In order to limit the number of images we propose the calculation of an optimal trajectory for the camera according to intrinsic and extrinsic constraints.