Special Purpose Lenses

Special purpose lenses are meant for specific purposes, they are classified as Fisheye, Micro and Perspective Control. As the name suggested, a Fisheye lens will give high distortion to the subject. Micro Lens are used to focus on objects that are small and needs detailing and Perspective Control allows user to minimize distortion to subject by changing it tilt angle.
These lenses are also of non-variable focal length. Below are some of the examples of the range of focal length in each type.