Shanghai Optics Stock Fisheye Lenses 1/4″SO-FE-15-24

A fisheye lens is a type of wide angle lens which can capture an extremely wide field of view. While a rectilinear wide angle lens can capture a field of view of 100 degrees, the fisheye lens can capture a field of view ranging from 100 to 180 degrees but with a circular image. Such lenses introduce a large amount of barrel distortion and straight lines are only possible at the center of the frame. They are especially designed to create a wide panoramic or hemispherical view without blind spots. Fisheye lenses are widely used in a variety of applications such as sky projection and dome movie projection in the planetariums, surveillance cameras, car cameras, security cameras, scientific photography, etc. Based on how the image circle fulfills the camera sensor, camera fisheye lenses can be categorized by two different types: diagonal fisheye lens and circular fisheye lens. A diagonal fisheye lens refers to a fisheye lens which is designed to have a 180-degree field of view over the sensor diagonal. For this kind of fisheye lens, the actual horizontal and vertical field of view of the rectangular image are smaller than 180 degrees. A circular fisheye lens refers to a fisheye lens which is designed to have a 180-degree field of view over the sensor width. Since an image sensor usually is rectangular and diagonal length is larger than the fisheye image circle diameter, the corners of the image are completely black. The focal length of fisheye lenses is short and its value is determined by the sensor format. For a (35 mm film) full frame sensor, usually focal length of fisheye lenses is not larger than 10 mm for circular images, and not larger than 16 mm for full-frame images. The focal length of fisheye lenses can be as short as 1 to 2 mm for digital cameras using smaller electronic imagers such as, 1⁄4 “, 1⁄3′ and 1⁄2” format CCD or CMOS sensors.