Almost every aspect concerning the design of modern panoramic lenses brings new challenges to optical designers. Examples of these include ray tracing programs having problems finding the entrance pupil which is moving through the field of view, production particularities due to the shape of the front lenses, ways of tolerancing these systems having strong distortion, particular setups required for their characterization and calibration, and algorithms to properly analyze and make use of the obtained images. To better understand these modern panoramic lenses, the Optical Engineering Research Laboratory at Laval University has been doing research on them during the past few years. The most significant results are being presented in this paper. Controlled distortion, as in commercial panomorph lenses (Immervision), is used to image a specific part of the object with more pixels than in a normal fisheye lens. This idea is even more useful when a zone of interest vary in time with dynamically adjustable distortion as in a panoramic locally magnifying imager. Another axis of research is the use of modern computational techniques such as wavefront coding in wide-angle imaging systems. The particularities of such techniques when the field of view is large or with anamorphic imagers are considered. Presentation of a novel circular test bench in our laboratories, required to calibrate and check the image quality of wide-angle imaging system, follows. Another presented setup uses a laser and diffractive optical elements to compactly calibrate wide-angle lenses. Then, a discussion of the uniqueness in tolerancing these lenses, especially the front elements due to the large ratio between lens diameter and entrance pupil diameter, is included. Lastly, particularities with polarization imaging and experiments of triangle orientation detection tests before and after unwrapping the distorted images are briefly discussed.

Date Published: 5 December 2011
PDF: 10 pages
Proc. SPIE 8197, 2011 International Conference on Optical Instruments and Technology: Optical Systems and Modern Optoelectronic Instruments, 81970I (5 December 2011); doi: 10.1117/12.910453

Published in SPIE Proceedings Vol. 8197:
2011 International Conference on Optical Instruments and Technology: Optical Systems and Modern Optoelectronic Instruments
Yongtian Wang; Yunlong Sheng; Han-Ping Shieh; Kimio Tatsuno, Editor(s)