Fisheye lens distorts straight lines into ridiculous curves. Straight lines, depending on where they are in the photo can be pulled a lot, a little, or not at all. The farther they are from the the center line of the photo, the more distortion there is. The closer the line is to the midpoint of the X or Y axis of the lens, the straighter the line will be.
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