This PDF file contains the front matter associated with SPIE Proceedings Volume 11106, including the Title Page, Copyright information, Table of Contents, Author and Conference Committee lists

Zoom lens design is inherently more complicated than is the design of fixed-focus lenses, and workers have traditionally been faced with a staggering amount of labor before the design is complete. One must calculate the first-order properties and the motions of the several lens groups while correcting image aberrations at many points in the zoom, over the field, in many colors, while keeping the image size and location stationary. That is not easy. The process was difficult, tedious, and often frustrating.

Anamorphic lenses entered the world of photography and cinematography quite a century ago. Since then, the propose of anamorphic lenses changed from increasing the field of view without increasing the image format on film material, to the creation of the most exciting images ever seen. Specific for anamorphic lenses is the different focal length in two perpendicular planes inside the lens system. This implies the use of asymmetric and rotational symmetric optical elements together in the same lens system. The design process becomes more difficult and time consuming than that for designing rotational symmetric lenses because in order to cover all aspects of lens performance within the optimization process, more rays have to be traced. Therefor it is mandatory for the lens designer to know what design means and techniques are to be used for accelerating the design process. This paper describes all development directions of anamorphic prime and zoom lenses since their invention. Different types of anamorphic solutions are evaluated, showing advantages and disadvantages and optimal structures and power distributions inside the lens system. This gives the designer the best options for designing this type of lenses.

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.

Choosing first-order group focal lengths for complex zoom lenses is a problem with too many variables to have a simple analytical solution. Furthermore, the group power balance has a large impact on performance, but there isn’t a well-known way to quickly determine the potential design performance of a given power grouping. This often leads to the choice of poor starting points increasing both the difficulty of the design process and the time to find a solution. To solve this problem (e.g. for a four-group zoom lens) a Monte Carlo like program has been written that first randomly chooses group focal lengths, finds first-order solutions, and checks for zoom group collisions. Then if a solution is valid it creates a lens design which is quickly optimized and evaluated for performance with real ray tracing using CODE V. The program keeps track of all solutions and is then able to automatically sort and identify power groupings with strong performance, simplifying the overall design process. Data collected by the program can also be used to sort solutions for minimum diameter, minimum length, and other design parameters.

Imaging optical systems require careful analysis and planning for successful production. Key steps should include evaluating the system sensitivities, manufacturability, and developing and understanding of parameters for tolerancing. In zoom lenses these steps are even more critical due to added complexity. Fundamental zoom lens assessment for manufacturability and tolerancing, including case study information, are discussed.

This paper starts with a description of the usability and the optical layout of an Abbe or Telescope type surgical microscope for stereo optical and stereo digital imaging. Most important optical characteristics for stereoscopic image aquisition are emphasized. Afocal Galilei-type optical zooms are the heart of all modern stereo microscopes for industrial, bioscience and surgical applications. Two type of such zooms are described:

Type 1: two separate optical channels, one for each stereoscopic view and.

Type 2: one common optical channel for both stereoscopic views each guided off-axis.

Type 1 zooms have the advantage of compact size and high optical quality. Their downside are tight tolerances and adjustment of optical members required for a good binocular performance. Type 2 zooms are always good at binocular even for standard tolerances but suffer from magnification dependency of the stereoscopic perception and from nonsymmetrical vignetting. Design examples are provided and some important aspects of aberration correction are discussed. As a vignetting-free system, one afocal commom optical channel Kepler-type zoom design example is proposed.

Finally, some advanced surgical microscope setups suitable for two stereoscopic observers in one microscope having different stereoscopic perspectives on the magnified object are shown. The Type 2 common optical channel zoom of Galilei or Kepler type is the best choice if a variable rotation position of a stereoscopic co-observer is required.

Stereomicroscopes allow us to observe specimen structure three-dimensionally and perceive their depth. In general, three-dimensional images are derived from the brain’s interpretation of the two slightly different images received from each of the retinas. Stereomicroscopes utilize the functions of both eyes and brain to perceive depth by transmitting two images tilted at a small angle to generate stereoscopic vision. These microscopes are necessary for specimen micromanipulation or examination required in a large and comfortable working space. Some other features such as the wide field of view and variable magnification are also helpful for industrial micro-assembly, or for biological research that needs careful manipulation and vulnerable living organisms. However, a demand for wider variable magnification range has been increasing along with the various applications. We reported the “Perfect Zoom System” which can make some of the zoom lens groups move perpendicular to the optical axes in the low-power state as a solution to this problem in 2015. This technique improves the zoom ratio and enables more applications with additional parts. Here, we review developments in stereomicroscopes with the “Perfect Zoom System” and discuss its practical applications.

UHDTV has entered the practical stage, as exemplified by the start of 4K/8K satellite broadcasting in December 2018 in Japan. Advancements in broadcast television camera systems is remarkable with 2/3-inch tri-sensor cameras evolving from HDTV to 4K, while at the same time 4K optical performance has been achieved for the associated interchangeable lenses. A contemporary requirement for broadcast television lenses is extra high zoom ratios that offer dynamic and seamless moving image expression, while avoiding lens exchange during live productions such as sports broadcasts and concert stage performances.

In this paper, we introduce the optical design concept applied to the latest 2/3-inch 4K zoom lens having a higher than 80x zoom range. The paper will further explain how Canon has realized 4K optical performance – while maintaining physical size and zoom ratio equivalent to the latest HDTV lenses – by referring to patent-pending technologies encompassing optical power layout, lens construction, and glass material combinations.

Demanding consumer digital imaging applications require excellent aberration correction during optical zoom. Object shifting in an optical system induces astigmatism that depends on the spherical aberration of the pupil. Although a zoom lens also refocuses and changes optical power for different configurations, obtaining the simplest configurations with astigmatism correction also requires correction of the spherical aberration of the pupil. Analysis of image quality for these factors should include focal corridor assessment across the field-of-view using an appropriate metric such as through-focus MTF. This paper discusses zoom lens correction and analysis based on these principles that enables quality consumer digital imaging products.

The design study herein analyzes the design complexity of high zoom ratio lens systems in the visible, SWIR, and LWIR spectrums with four zoom groups (two internally moving). The aforementioned 12.5x zoom lens systems have been designed for use in the Coast Guard for maritime safety, security, and stewardship. To begin our comparative design study, the most advantageous solutions for distinct power groupings were found using a first order solution finder tool. The results showed that solutions with a PNNP, PNPP, and NPNP power grouping with the aperture stop in the third or fourth group had the most potential. At the end of the design process, a comparison was done for the three different wavebands to analyze the relative design complexity. Design complexity metrics were as follows: element count, number of aspheric surfaces, system total track length, element diameter, and tolerance sensitivity.

DOE is diffractive optics or diffractive optics elements, it is also called DO or PF (Phase Fresnel). It is usND mainly for chromatic aberration correction (controlling color aberration) purposes. On the process of using DOE, wider variety of lens elements turns available for temperature compensation.

The optical design of a 3X zoom lens suitable for incorporation into a modern smartphone is described in detail. Particular emphasis is applied to techniques for achieving the required small size, extremely high image quality and the need to maintain at least an f/2.8 speed throughout the zoom range so as to minimize image quality loss due to diffraction. Because modern camera software allows for the correction of certain types of off-axis chromatic and distortion aberrations, optical designs offering both full and partial correction of these aberrations are presented. With such correction being obtained within the camera, optical designs containing fewer than ten lens elements are attainable, making the optical complexity comparable to that of current two-lens non zoom solutions. The presentation will include complete optical designs together with full prescriptions and illustrations of image quality.

This paper introduces a design of telephoto zoom lens with the built-in teleconverter, focusing on the AF-S NIKKOR 180-400mm f/4E TC1.4 FL ED VR. In recent years, professional photographers are demanding more convenience and higher image quality. For these needs, we developed the AF-S NIKKOR 180-400mm f/4E TC1.4 FL ED VR telephoto zoom lens, by improving its usability and optical performance compared to the previous model. Especially in terms of optics, we 1) expanded the focal length of the wide-angle end from 200mm to 180mm, 2) integrated 1.4x teleconverter, 3) designed it in consideration of its usability (e.g. weight, torque of zoom or focusing ring, diameter of lens barrel) . The above features have achieved by using 4-group zoom type design consisting of PNPP (positive, negative, positive and positive), and separating the focus part from the zoom part.

It will further explain how we have simultaneously realized high optical performance and usability, especially focusing on optimized optical power distribution, lens configuration, glass material combination and layout of functional lens groups (e.g. image stabilization, the built-in teleconverter).

I will introduce test items and measuring methods for camera lenses in the “New Face Clinic” of the “Photography Journal, Asahi Camera” that is a monthly magazine for camera and photo enthusiasts. In that article, we introduce the lens configuration, special glass material, aspheric surfaces, coating type first. The main test items are focal length, open aperture value, spherical aberration, curvature of field, astigmatism, distortion, and modulation transfer function (MTF). Also, we actually shoot distant views, point light sources, close-up shots and evaluate images through the eyes. Although the test results are mixture of the effect of the image processing and physical lens performance, we measure Spatial Frequency Response (SFR). Finally, we evaluate the lenses comprehensively from these test results.