We are studying the geometry of a 360 x 360 mosaic image formation. A 360 x 360 mosaic camera model and a calibration procedure are proposed. It is shown that only one point correspondence is needed in order to acquire epipolarily rectified images. The 360 x 360 mosaic camera model is therefore determined by only one intrinsic parameter. It is shown that the relation between coordinates estimated with different values of intrinsic 360 x 360 mosaic camera parameters is a scaling of all scene point coordinates with additional nonlinear changes in the z coordinates of the scene points. Experimental results verifying the reconstruction of real scene points are presented.