An imaging system comprises four image sensors each pointing outwardly from the vertices of a notional tetrahedron with the optical axes of the image sensors substantially collinear with respective medians of the notional tetrahedron, with the focal plane array of each image sensor positioned between the lens system of its respective image sensor and the centroid of the notional tetrahedron. The imaging system and can be used to obtain image data for generating a spherical image of the space surrounding the imaging system. A method for generating a spherical image from this image data assigns spherical coordinates to the pixels in the images according to a cylindrical projection that is individually aligned with the image plane of each image, and blends overlapping pixels and fills blank pixel spaces. The method can be applied to image data representing outward views from the vertices or centroids of faces of any Platonic solid.