Fisheye lens is a wide-angle lens that takes in an extremely wide, hemispherical image.The focal lengths of fisheye lenses depend on the film format.Fisheye lenses achieve extremely wide angles of view by forgoing a rectilinear image, opting instead for a special mapping (for example: equisolid angle), which gives images a characteristic convex appearance. A panorama by rotating lens or stitching images (cylindrical perspective) is not a fisheye photo. Fisheye lens showed in picture is used for Sanyo projector XM-1000C,5000 Lumen.We could manufacture and design kinds of fisheye lens as reqeusted. Total length of the projector lens is 109.2mm,external diameter of small end is 77mm,external diameter of big end is 134mm