This PDF file contains the front matter associated with SPIE Proceedings Volume 8489, including the Title Page, Copyright information, Table of Contents, and the Conference Committee listing.

After more than a century from the introduction of zoom lenses, the selection of the right zoom lens type for a given specification is still a challenge for the optical designer. In the process of lens design, the optical designer is permanently searching for the best zoom lens structure in order to fulfill the complex balance between weight, cost and optical performance. This is a continuous optimization process and the result is a global optimum. The most important factors influencing zoom lens cost are: the number of spherical and aspherical lenses, the number of moving groups and lenses and finally the group sensitivity to displacement and tilt. Every lens group whether moving or not inside the zoom lens, has a specific complexity and sensitivity behavior dependent on the zoom lens type. It is not obvious which type of zoom lens will optimally satisfy the required specification. This paper describes the selection process exemplary for a zoom lens with a medium focal length range from 28mm to 80mm and a quasi constant f-number (FNO) during zooming. The lens is used mainly for cinematographic applications and must be able to maintain best image position for the entire range of object positions during zooming. Alternative solutions with their advantages and disadvantages are shown, analyzed and evaluated.

Proposed method uses aberration coefficients analysis which was in use in the period before computers wide application for optical design. We consider that this method was undeservedly forgotten and in combination with modern software it can provide better maintenance of aberration correction and understanding of zoom lenses aberration analysis and construction. Equations presented were received for the case of different zoom lenses constructions. Single, two and three components zoom lens are analyzed.

Many of observation optical systems consist of two parts: main observation objective with long focal length and narrow angular field and wide angular viewfinder lens. We propose to combine the two mentioned optical systems in one varifocal objective. In this case refractive system of viewfinder is integrated into the scheme of the catadioptric objective. Changing of magnification is implemented by “replacing” certain optical-mechanical components either in main or in viewfinder objective. In this paper it is described optical design of proposed approach and its technical realization.

A review paper has been previously published on infrared zoom lenses in the 1980s¹. Subsequently, a paper was published on infrared zoom lenses in the 1990s². It is timely to prepare a paper on developments and trends in infrared zoom lenses in the decade since the year 2000. These trends include the shift from scanning systems to CCD and focal plane arrays, dual band systems, advances in simulators for target detection, high zoom magnification ratio, reflective zoom systems, and developments and trends in infrared materials and detectors. Examples are presented to illustrate each of these trends. These examples are predominently mechanically compensated zoom lenses, although one optically compensated zoom lens is also included.

Zoom lens design requires a very strong understanding of geometrical optics and how it directly relates to an optical system. Understanding both first-order optics and pupil conjugation is absolutely essential to ensure that a lens zooms correctly and avoids discontinuities. This tutorial paper explains these first-order considerations in detail and illustrates how to derive a starting configuration. The tutorial also shows how to proceed toward a final lens optimization.

High density digital sensors combined with "digital zooming" have eliminated the need for many small magnification range zoom lenses. Instead, lens designers now must design and assess zoom lenses for ever-increasing magnification ranges. The number of zoom positions for designing and assessing must increase as well, but assessing multi-spectral Modulation Transfer Function (MTF) data for many zoom positions becomes overwhelming. In this paper an efficient and effective metric, Area-Weighted Modulation-Cycles (AWMC), is proposed and reviewed for assessing imaging properties efficiently in a zoom system.gh density digital sensors combined with "digital zooming" have eliminated the need for many small magnification range zoom lenses. Instead, lens designers now must design and assess zoom lenses for ever-increasing magnification ranges. The number of zoom positions for designing and assessing must increase as well, but assessing multi-spectral Modulation Transfer Function (MTF) data for many zoom positions becomes overwhelming. In this paper an efficient and effective metric, Area-Weighted Modulation-Cycles (AWMC), is proposed and reviewed for assessing imaging properties efficiently in a zoom system.

Afocal zoom lenses are state of the art modules for magnification changing in instrument optics, especially in the field of scientific and surgical stereo microscopy. Carl Zeiss implemented many types of afocal zoom lenses in the microscopy instrumentation in more than 30 years. Mechanically compensated zooms with two moving members for magnification range between 4x and 20x are the most widely used zoom lenses so far. As the instrumental optics gradually moves towards the digital imaging, some modified schemes have been created in order to meet new requirements for extended zoom range and for accessibility to the system pupil by an aperture stop or by a shutter. A structure and particular aberration analysis of a four member afocal 20x zoom lens is discussed. It is pointed out that a modular approach for instrumental digital imaging systems with afocal interfaces around the zoom module is one promising application of afocal zooms in the future. This approach contains an afocal zoom with an accessible central stop surrounded by focusing lens groups placed on the object and / or at the image side of the zoom. The advantages of schemes like that are the easy scaling to high magnification range, good balancing of aberrations and diameters of lens elements and the high flexibility in adaption of video systems to different applications. Two examples of modular video zoom lenses are given: an object-side telecentric 20x zoom lens with a four member afocal zoom and a telephoto-type 30x zoom lens with a three member afocal zoom.

Laparoscopic lens module that is capable of zooming is presented. The lens module has a high magnification and a high resolution such as four zoom and 2M pixels full HD image. The lens module consists of two lens sets to get 3-D images. Each lens module has several lenses less than conventional laparoscope but has 8 lenses and two liquid lenses. The total length of module is 19 mm long and the diameter is less than 5 mm. The separated distance of two lens center is 5 mm and two lens modules are inserted into the 11mm diameter laparoscope. The lens module is designed by Code V™ by using the 2M pixels CMOS sensor that the pixel size is 1.75 μm. The merit of this fluidic lens design is being convertible between a convex and concave shape. The effective focal length of zoom-out and zoom-in modes is 3.24 mm and 12.94 mm respectively. The modulation transfer function of zoom-out and zoom-in modes is 40% and 30% at 140 lp/mm frequency. We have a diffraction of element at near stop to improve image resolution. Also the resolution of zoom-in mode is improved by using liquid iris. The F-number of a two modes is 4.4 and 5.8 and the optical distortion is 10% and 0.5%. It is expected that the z-direction resolution by this laparoscope is less than 2 mm

Cygnus is a high-energy radiographic x-ray source. The rod-pinch x-ray diode produces a point source measuring 1 mm diameter. The target object is placed 1.5 m from the x-ray source, with a large LYSO scintillator at 2.4 m. Differentsized objects are imploded within a containment vessel. A large pellicle deflects the scintillator light out of the x-ray path into an 11-element zoom lens coupled to a CCD camera. The zoom lens and CCD must be as close as possible to the scintillator to maximize light collection. A telecentric lens design minimizes image blur from a volume source. To maximize the resolution of test objects of different sizes, the scintillator and zoom lens can be translated along the x-ray axis. Zoom lens magnifications are changed when different-sized scintillators and recording cameras are used (50 or 62 mm square format). The LYSO scintillator measures 200 × 200 mm and is 5 mm thick. The scintillator produces blue light peaking at 435 nm, so special lens materials are required. By swapping out one lens element and allowing all lenses to move, the zoom lens can also use a CsI(Tl) scintillator that produces green light centered at 550 nm. All lenses are coated with anti-reflective coating for both wavelength bands. Two sets of doublets, the stop, and the CCD camera move during zoom operations. One doublet has XY compensation. The first three lenses use fused silica for radiation damage control. The 60 lb of glass inside the 340 lb mechanical structure is oriented vertically.

Development of compact optical zoom lenses for integration in mobile phones is the goal of many companies. Optical zoom lenses change their focal length by the movement of lens elements or change in surface curvature or refractive index and this complicates the zoom lens design. Extended depth-of- field (EDOF) techniques provides the mean to simplify and miniaturize zoom lens designs with moving lens elements and a new EDOF optimization technique is presented. Finally, the starting point and an example of a compact optical zoom lens design with EDOF is also described.

The thickness of the smart phones in today’s market is usually below than 10 mm, and with the shrinking of the phone volume, the difficulty of its production of the camera lens has been increasing. Therefore, how to give the imaging device more functionality in the smaller space is one of the interesting research topics for today’s mobile phone companies. In this paper, we proposed a thin optical zoom system which is combined of micro-electromechanical components and reflective optical architecture. By the adopting of the MEMS deformable mirrors, we can change their radius of curvature to reach the optical zoom in and zoom out. And because we used the all-reflective architecture, so this system has eliminated the considerable chromatic aberrations in the absence of lenses. In our system, the thickness of the zoom system is about 11 mm. The smallest EFL (effective focal length) is 4.61 mm at a diagonal field angle of 52° and f/# of 5.24. The longest EFL of the module is 9.22 mm at a diagonal field angle of 27.4 with f/# of 5.03.°

Miniaturization is the key point to design image system for portable devices. Motor-driven lens technique is the traditional way to achieve auto-focus and zoom functions, this method usually requires a larger space and causes greater power consumption. Reflective optics is a technology not only can make the space application become more efficient and flexible, but also has the advantage that it induces low chromatic aberrations. In this paper, we use organic deformable mirror (DM) as reflective element of the system. PDMS used as an actuated membrane of DM has lower young's modulus and residual stress. The maximum stoke is 90 um and corresponding diopter is 39.964m(^-1) . The system we designed with MEMS deformable mirror is a 5M pixel zoom image system which is only 10mm in thickness before packaging and 16mm in thickness after packaging. The smallest EFL (effective focal length) is 4.7 mm at full field angle of 52° and the f/# is 4.4. The longest EFL of the module is 9.4 mm and the f/# is 6.4.

Although digitalization has tripled consumer-class camera market scale, extreme reductions in prices of fixed-lens cameras has reduced profitability. As a result, a number of manufacturers have entered the market of the System DSC i.e. digital still camera with interchangeable lens, where large profit margins are possible, and many high ratio zoom lenses with image stabilization functions have been released. Quiet actuators are another indispensable component. Design with which there is little degradation in performance due to all types of errors is preferred for good balance in terms of size, lens performance, and the rate of quality to sub-standard products. Decentering, such as that caused by tilting, sensitivity of moving groups is especially important. In addition, image stabilization mechanisms actively shift lens groups. Development of high ratio zoom lenses with vibration reduction mechanism is confronted by the challenge of reduced performance due to decentering, making control over decentering sensitivity between lens groups everything. While there are a number of ways to align lenses (axial alignment), shock resistance and ability to stand up to environmental conditions must also be considered. Naturally, it is very difficult, if not impossible, to make lenses smaller and achieve a low decentering sensitivity at the same time. 4-group zoom construction is beneficial in making lenses smaller, but decentering sensitivity is greater. 5-group zoom configuration makes smaller lenses more difficult, but it enables lower decentering sensitivities. At Nikon, the most advantageous construction is selected for each lens based on specifications. The AF-S DX NIKKOR 18-200mm f/3.5-5.6G ED VR II and AF-S NIKKOR 28-300mm f/3.5-5.6G ED VR are excellent examples of this.

The digital camera market has extremely expanded in the last ten years. The zoom lens for digital camera is especially the key determining factor of the camera body size and image quality. Its technologies have been based on several analog technological progresses including the method of aspherical lens manufacturing and the mechanism of image stabilization. Panasonic is one of the pioneers of both technologies. I will introduce the previous trend in optics of zoom lens as well as original optical technologies of Panasonic digital camera "LUMIX", and in addition optics in 3D camera system. Besides, I would like to suppose the future trend in digital cameras.

Recent development in CMOS and digital camera technology has accelerated the business and market share of digital cinematography. In terms of optical design, this technology has increased the need to carefully consider pixel pitch and characteristics of the imager. When the field angle at the wide end, zoom ratio, and F-number are specified, choosing an appropriate zoom lens type is crucial. In addition, appropriate power distributions and lens configurations are required. At points near the wide end of a zoom lens, it is known that an aspheric surface is an effective means to correct off-axis aberrations. On the other hand, optical designers have to focus on manufacturability of aspheric surfaces and perform required analysis with respect to the surface shape. Centration errors aside, it is also important to know the sensitivity to aspheric shape errors and their effect on image quality. In this paper, wide angle cine zoom lens design examples are introduced and their main characteristics are described. Moreover, technical challenges are pointed out and solutions are proposed.

With the advent of digital camera systems which provide high performance imaging combined with reduced size, weight and cost, this has created a demand for zoom lenses to meet new specific requirements. In addition, there is also a need to meet preferred optical characteristics; therefore, contemporary zoom lens optical designs may become less attractive for use with modern digital camera systems. Zoom lens optical designs which more closely match digital camera requirements such as high resolution, high contrast, high relative illumination (for low picture shading), low residual chromatic aberration and near telecentric radiation output at the image sensor, are described in this paper. To achieve the desired requirements, the optical design power configuration of these zoom lenses comprise four lens groups, with a first negatively powered lens group followed by three positively powered lens groups. To provide zooming, a movable optical stop is located after the negatively powered lens group and is followed by two positively powered movable lens groups. Additional features including low ‘breathing’ throughout the focus and zoom ranges are also described via the optical design examples given.

The zoom lens design problem for the 2012 Zoom Lens IV conference is a first of its kind. The challenge is to design a lens operating at a single wavelength of 587.6 nm with a 20:1 zoom ratio using only four elements; akin to the 1990 IODC Monochromatic Quartet design problem. The lens design offers several degrees of freedom including a range of glass and aspheric elements in order to achieve the continuous zoom through effective focal lengths from 4 mm to 80 mm, with a back focal length > 16 mm. Throughout the zoom motion, the first element and the aperture stop are kept in fixed positions relative to the image plane and lens operates at a constant f/10. The goal of the problem is to minimize the length of the system as measured from the vertex of the front element to the image plane. The design is required to meet an RMSWFE < 0.07 waves to a field height of 1.25 mm, while supporting a full field height of 2.5 mm with less than 5% magnitude distortion. The winning entry met the specifications with a length of only 22.195 mm.