Patent attributes
A fisheye lens, comprising a front group made up of a total of three groups, which are two concave lenses 1 and 2 whose concave surfaces are directed toward the image side, and a compound lens 3 whose concave surface is directed toward the image side and which has an overall convex or concave refractive power; and a rear group formed by three groups of convex lenses 4, 5, and 6, wherein the front group includes at least one compound lens set, the rear group includes one compound lens set, and at least a first surface of a first concave lens 1 of the front group is an aspheric surface, and satisfies specific conditions. As a result, it is possible to obtain a fisheye lens that can realize a foveal optical system with undiminished illuminance all the way to the periphery and with high resolution over the entire field of view, and with which a wide field of view and an extremely compact size can be attained with a single wide-angle optical system.
