Method of confocal mirror design

We provide an overview of the method of confocal mirror design and report advances with respect to pupil imagery. Two real ray-based conditions, Y+ = -Y- and Delta Y = 0, for the absence of linear astigmatism and field tilt are presented. One example illustrates the design of a system confocal of the object and image, and another illustrates the design of a system confocal of the pupils. Stop shifting formulas are provided. Three three-mirror anastigmatic systems further illustrate the method. (C) 2019 Society of Photo-Optical Instrumentation Engineers (SPIE)This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Ray Tracing Methods for Correcting Chromatic Aberrations in Imaging Systems

The correction of chromatic aberrations is typically performed using aberration formulas or by using real ray tracing. While the use of aberration formulas might be effective for some simple optical systems, it has limitations for complex and fast systems. For this reason chromatic aberration correction is usually accomplished with real ray tracing. However, existing optimization tools in lens design software typically mix the correction of monochromatic and chromatic aberrations by construction of an error function that minimizes both aberrations at the same time. This mixing makes the correction of one aberration type dependent on the correction of the other aberration type. We show two methods to separate the chromatic aberrations correction of a lens system. In the first method we use forward and reverse ray tracing and fictitious nondispersive glasses, to cancel the monochromatic aberration content and allow the ray tracing optimization to focus mainly on the color correction. On the second method we provide the algorithm for an error function that separates aberrations. Furthermore, we also demonstrate how these ray tracing methods can be applied to athermalize an optical system. We are unaware that these simple but effective methods have been already discussed in detail by other authors

Phase plates for generation of variable amounts of primary spherical aberration

We discuss a set of phase plate-pairs for the generation of variable amounts of primary spherical aberration. The surface descriptions of these optical plates are provided, and their aberration-generating properties are verified with real ray-tracing. These plate-pairs are robust in that they allow large tolerances to spacing as well as errors in the relative displacement of the plates. Both primary spherical aberration (r4) and Zernike spherical aberration (6r4- 6r2 + 1) can be generated. The amount of spherical aberration is proportional to the plate-pair displacement and in our example it reaches up to 48 waves (~8 waves Zernike) for a clear aperture of 25 mmThis work was supported by the Spanish Ministerio de Educacion y Ciencia grant FIS2010-16753 and the FEDER and performed during the sabbatical stay of E. Acosta at the University of ArizonaS

Towards Euclidean auto-calibration of stereo camera arrays

Multi-camera networks are becoming ubiquitous in a variety of applications related to medical imaging, education, entertainment, autonomous vehicles, civil security, defense etc. The foremost task in deploying a multi-camera network is camera calibration, which usually involves introducing an object with known geometry into the scene. However, most of the aforementioned applications necessitate non-intrusive automatic camera calibration. To this end, a class of camera auto-calibration methods imposes constraints on the camera network rather than on the scene. In particular, the inclusion of stereo cameras in a multi-camera network is known to improve calibration accuracy and preserve scale. Yet most of the methods relying on stereo cameras use custom-made stereo pairs, and such stereo pairs can definitely be considered imperfect; while the baseline distance can be fixed, one cannot guarantee the optical axes of two cameras to be parallel in such cases. In this paper, we propose a characterization of the imperfections in those stereo pairs with the assumption that such imperfections are within a considerably small, reasonable deviation range from the ideal values. Once the imperfections are quantified, we use an auto-calibration method to calibrate a set of stereo cameras. We provide a comparison of these results with those obtained under parallel optical axes assumption. The paper also reports results obtained from the utilization of synthetic visual data

Some displays of lens structural performance

Some useful displays that provide information about the performance of lens systems are presented and discussed in this paper. They are useful for comparing lenses, identifying problematic lens elements, and lens desensitizing and optimizing. An imaging simulation of a square wave is also presented to complement the modulation transfer function plots.12 month embargo; published: 2 November 2021This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Joseph Petzval lens design approach

We pose that there is enough information left to reconstruct Petzval lens design approach, and answer the question of how Joseph Petzval design his famous portrait objective.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Aberrations of zoom lens kernel

This paper discusses the aberrations of a zoom lens kernel and a method to determine them. Separating the kernel aberrations provides insight into the zoom lens design process and helps the process by decoupling design tasks. The design of a zoom lens is discussed, step by step, and some alternate kernel solutions are shown. A technique for controlling uniform aberrations is discussed, and a reverse ray tracing method for displaying kernel aberrations is presented. The role of pupil coma in controlling distortion is also discussed.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Enhancements and applications of induced aberration theory

Intrinsic and induced aberrations can be important contributors to the total aberration content of a lens. Theory for induced aberrations has been explored and recently advanced. Macros for calculating and targeting intrinsic and induced aberrations have been written. We briefly discuss wave aberration theory and induced aberration theory, including algorithmic advancements. We demonstrate the application of the recent theory and new macros in lens optimization.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Aspheric/freeform optical surface description for controlling illumination from point-like light sources

We present an optical surface in closed form that can be used to design lenses for controlling relative illumination on a target surface. The optical surface is constructed by rotation of the pedal curve to the ellipse about its minor axis. Three renditions of the surface are provided, namely as an expansion of a base surface, and as combinations of several base surfaces. Examples of the performance of the surfaces are presented for the case of a point light source. (C) 2016 Society of Photo-Optical Instrumentation Engineers (SPIE)This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]