Combinations of achromatic doublets chapter 8 introduction to. The most common type of achromat is the achromatic doublet, which is composed of two individual lenses made from glasses with different amounts of dispersion. In many cases, it is not sufficient to use a simple doublet lens. Design a modern optical system requires the integration of expertise in widely different fields such as, lens design, thermal and mechanical analysis, sensors, etc. This book describes the optical performance of most of the types of telescope bought or built and used by amateurs, and explains why some are suitable for visual observations, and others for photography, some for lunar and planetary work, others for faint and extended objects like nebulae or star clusters.
Detailing design methods for a variety of lens forms, this book shows that fixed focus and zoom lenses can be optimized, starting from planeparallel surfaces, in a brief time on a. In summary, we can see that for a given set of glasses, the design process works by altering only three parameters. It was assumed that the readership would possess a wide range of levels of antenna sophistication, from the novice newbie to the professional engineer. Achromatic lenses are used to minimize or eliminate chromatic aberration. By this procedure, based upon the experience of the designer, a basic lens type is. Free version of the winlens3d optical design package, which provides serious design and analysis tools for optical engineer, student or designer. Modern lens design mcgrawhill professional engineering. It was with surprise and delight that i noted that clerks in one radio. Inset shows the detailed design of the cuvette holder. Specifically, red light is focused farther from the lens than blue light. These can suppress false colour even when low focal ratios in the range f5 to f7 are used and so provide the wider fields of view prized by both.
Continuing the bestselling tradition of the authors previous books, lens design, fourth edition is still the most complete and reliable guide for detailed design information and procedures for a wide range of optical systems. But all of these software packages share one critical flaw. Achromatic and apochromatic refractor designs starizona. These doublet lens sets are more economical to buy compared to buying as individual lenses. To illustrate the kind of record required in the manual tracing of a skew ray by these formulas, we. Contact our multilingual technical sales team and discover how knight opticals high quality custom achromatic doublet lenses. Therefore, this book can be used with any lens design software. A schematic diagram is not good enough in my opinion, i. Achromatic lenses are ideal for a range of applications, including fluorescence microscopy, image relay, inspection, or spectroscopy. Enter doublet focal length, select a glass type for both front and rear lens from the schott glass catalog for example bk7 and f2.
The zemax code in the book is a bit dated by now but most users should be able to still use it for newer editions of the software. The design is also corrected for chromatic and spherical aberration, meaning that if you follow the design closely and your glasses are close to the standard values and polish your glass carefully. Splitting an element into two lenses which are very close together but with the same total refractive power. Clerks in radio stores told me that this book was outselling other titles 2. Lens design fundamentals second edition rudolf kingslake. Modern optical engineering the design of optical systems warren j. Pdf the initial approximations for achromatic doublets of the xviii. To design optical imageforming systems, we must model the propagation of light from the object source to the optic, the action of the optic on the incident light distribution. The section concludes with several techniques for rapid estimation of the performance of lenses. Apparently this design of an achromatic doublet should be attributed to martin with the same right. Fisheye lens designs and their relative performance james jay kumlera, martin bauerb.
A combination of two lenses in contact, a converging lens made of crown glass and a weaker diverging lens made of flint glass, can be. Consider the cemented doublet lens, as described in section 2. There is no shortage of lens optimization software on the market to deal with todays complex optical systems for all sorts of custom and standardized applications. For a more basic overview of this design please see therefractors page. There are also many useful figures to help visualize the main issuesconsiderations of lens design. Neglecting very primitive systems, such as a one or twomirror system, or a singleelement lens, such a technique is presently not possible. The systematic method of lens design in use today is an iterative technique.
Includes history, technical examples, and performance evaluation of each. The achromatic design also helps minimize spherical aberrations. Achromatic doublets and more complex lens systems are covered next. Imaging is the most important application sector for achromatic optics. If there is space available to do it you can usually make a new well corrected design by flipping a nearly monocentric concentric lens over to the other side of its nearly common centers of curvature and then reoptimizing. In optics, a doublet is a type of lens made up of two simple lenses paired together. Obj, is focused by a doublet achromatic lens l1, f 200 mm to form a conjugate imaging plane where a mechanical pupil a is placed to control the aperture size. Visible mgf 2 antireflection coated achromatic doublet lenses. A hyperchromatic lens is a cemented doublet lens that has the same index of refraction at the primary wavelength, but different dispersion or abbe number.
Telescope optics, a comprehensive manual for amateur. A subtype of airspaced doublet is the dialyte, a design where elements are. They confirmed that the types of people who buy the book meet the profile above. Continuing the bestselling tradition of the authors previous books, lens design, fourth edition is still the most complete. The initial approximations for achromatic doublets of the. I honestly think those nasty fake pdf sites that use loads of domains and look the same are sponsored by the publishers, theyre really effective at masking any legit pages. Although zemax is easy to use, optical system design is a very broad area of engineering. Automatic and quasiautonomous computational methods and techniques is the first book that interactively describes the newest modern lens design tools. You can see how a new design can evolve around a simple starting point idea or structure. Lens design is, therefore, a strong component of a wellrounded education in optics, and a skill valued by industries employing optical engineers. This will fill with data, the refractive indices fields n 1, n 2, n 3 for a fixed wavelengths and finally press the calc button. Circle of confusion from basic photographic materials and processes, stroebel et al.
This combination produces a better image than a simple lens. The main application of achromatic optics in particular, on a chromatic lenses is in imaging systems, as needed for photography, microscopy and video recording, for example. Doublet lens news newspapers books scholar jstor december 2009 learn how and when to remove this template message. Some trilobites, which are now extinct, had natural doublet lenses in. The achromatic doublet is a fundamental building block in lens design because it is corrected for chromatic aberrations, and can also be.
Triplet modified by replacing back element with doublet tessar greek four designed by paul rudolph in 1902 at zeiss optical in germany. Lenses and depth of field prepared by behzad sajadi. Refractors, objective lenses, optical assembly units, focusers and more are available. Designing an achromatic doublet physics libretexts. The complete design process from lens definition to the description and evaluation of lens errors on to the improvement of lens performance will be developed and illustrated using the program. We stock a range of doublet lens sets for ease of use in a laboratory and design environments. In spite of that, a lot of lens design books and textbooks that i have read rely heavily on the derivations of mathematical equations, without actual lens design data and figures and graphs, especially lens design diagrams. Fisheye lenses, optical design, relative illumination, distortion testing. Every system includes one aspheric surface and free positioned aperture stop.
Barry johnson, in lens design fundamentals second edition, 2010. The book not only covers theory of lens design but the author also delves into the math using practical examples. And this is all human based lens design where the fun part, and most important part, comes before we do any computer optimization. A representative variety of lenses is analyzed and discussed performance that may be expected of each class of lens is presented. Chapter 1 handbook of optics photonics research group. As a general rule of thumb, for lenses with identical specifications except for material, a bk7 lens will be cheaper to produce. The success of the three previous editions of practical antenna handbook has been most gratifying. Most optical tolerancing problems are far more complex, but this example provides an insight into the methods applied. Replacing a thick lens by two thin lenses, which have the same power as the two refracting surfaces. Refer to the application tab above for information about the superior performance of achromatic doublets compared to singlet lenses. Pdf automation design of cemented doublet researchgate. However, the design of an achromatic doublet lens lends itself to the sort of calculation we are doing in this chapter. Carisbad, california and consultant in optics and design third edition. An achromatic lens, which is often designed by either cementing two.
A doublet intraocular lens optimized for both chromatic and monochromatic aberration correction in pseudophak ic eyes is presented. Soft glasses are more difficult to polish to achieve very good cosmetics and low rms surface roughness. One is a singlet lens and the other is a doublet lens system. An achromatic lens or achromat is a lens that is designed to limit the effects of chromatic and spherical aberration. Quality achromatic doublet lenses commercial doublet. Achromatic lens achromatic lenses achromat edmund optics. The apochromatic lens is usually of three elements,but, in this paper used two element fig. The lenses are made from glasses with different refractive indices and different amounts of dispersion. This book is intended to introduce the mathematical tools that can be applied to model and predict. Raytr acing techniques were applied to design the lens in white. And the maximum field of a detector is fully filled with the same size of target object at the minimum approaching distance 50 m. Overview our visible mgf 2 coated achromatic doublet lenses feature minimized spherical aberration and coma at infinite conjugates, yielding minimal focus spot size. Often one element is made from crown glass and the other from flint glass. A simple lens focuses different wavelengths of light to different points.
Some trilobites, which are now extinct, had natural doublet lenses in their eyes. Unlike singlet lenses, achromatics have constant focal length independent of aperture and operating wavelength, and. Fisheye lens designs and their relative performance. The computer program oslo was used to design the work, but the writeups are programneutral. A complete breakdown of the double gauss lens design and the sonnar lens design.
For achromatic objectlens consisting of two glasses, it is necessary. The designs will differ in their higher order aberrations and in their length. Achromatic lenses are corrected to bring two wavelengths typically red and blue into focus on the same plane. A combination of two lenses in contact, a converging lens made of crown glass and a weaker diverging lens made of flint glass, can be designed so that the combination is a converging lens that is almost achromatic. The lens power factor of the first lens in a fraunhofer type doublet normally lies between 1. Achromatic doublets and more complex lens systems are covered. The design algorithm supposes that the operator has already chosen the glass sorts 2. For achromatic objectlens consisting of two glasses, it is. The calculated cemented doublet parameters can be analyzed and optimized in optical system design software. Achromatic doublets are useful for controlling chromatic aberration and are frequently used to achieve a diffractionlimited spot when using a monochromatic source like a laser.
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