We present the design of a spherical imaging system with the following properties: (i) A 4π field of view that enables it to "see" in all directions; (ii) a single center of projection to avoid parallax within the field of view; and (iii) a uniform spatial and angular resolution in order to achieve a uniform sampling of the field of view. Our design consists of a spherical (ball) lens encased within a spherical detector shell. The detector shell has a uniform distribution of sensing elements, but with free space between neighboring elements, thereby making the detector partly transparent to light. We determine the optimal dimensions of the sensing elements and the diameter of the detector shell that produce the most compact point spread function. The image captured with such a camera has minimal blur and can be deblurred using spherical deconvolution. Current solid state technologies do not permit the fabrication of a high resolution spherical detector array. Therefore, in order to verify our design, we have built a prototype spherical camera with a single sensing element, which can scan a spherical image one pixel at a time.© (2009) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.