Study of Fisheye Lens Attachments for Mobile Phone Lenses

Abstract

Fisheye lenses have a very special lens structure with an extremely wide field of view of about 170 degrees or more. They have some unique specifications, such as 100 percent barrel distortion, one of four different mapping functions, and relative illumination that does not follow the cos^4⁡〖(θ)〗 law. Based on these properties, fisheye lenses are popular in some scientific applications and panoramic photography. With the development of high-quality smartphone cameras, more and more people use their smartphone instead of dedicated cameras in their daily lives. Convertible smartphone camera kits can expand the photographic capabilities of smartphone cameras, and fisheye lens adapters are one type of kit. In this thesis, five systems, three having all spherical surfaces, are presented. They all have over 170 degrees field of view with an magnification more than 0.5 and achieve an RMS wavefront error less than 0.5 waves. An analysis for aberration correction as well as relative illumination is discussed in detail. In the last chapter, a slanted edge test is utilized to measure and analyze a commercial fisheye adapter’s MTF performance.