Optical engineers working in lens design will find this book an invaluable guide to lens design in traditional and emerging areas of application. Field flattener lenses counteract the petzval field curvature. Star images are tighter and more pointlike across the entire image with a field flattener or with a reducer lens that also has a fieldflattening function. Given that an inhouse lens design showed to be promising, it was decided to complete the design inhouse and have the lenses made by a lens manufacturing company. Rays from different points on the subject top, bottom, left, right will converge at different points on the other side of the lens, these focal points together make up the focal plane. Welcome to lens afield focusing on the natural world. Photography focusing on the natural world, closeup and intimate. This accessory is a musthave for refractor astrophotography. The trace window for a maksutovcassegrain telescope with field flattener lens is shown below. Whether in the hands of a hunter scouting a target, a birdwatcher looking for their favorite finch or a sports fan watching the batter swing, these binoculars offer outstanding image quality, speedy operation and an elegant, compact design. Bokeh is now a normal lens design parameter for very high quality lenses. To illuminate an extended area, it is necessary to expand the beam using a microscope objective with a pinhole spatial filter placed at its focus to eliminate random diffraction patterns due to scattered light spatial noise. Shop online for a wide selection of raylabcon lens paper cleans lenses and other delicate surfaces.
Some general questions about field flatteners posted in atm, optics and diy forum. The lens is generally the most expensive and least understood part of any camera. Hilux phenom ed field flattened binoculars are available in both 8x42 or 10x42 configurations. A diverging element placed immediately before the eyepiece, also know as a barlow, and sometime a smyth lens. Offers optimal field correction and illumination for sensors up to 45mm diagonal. A schmidtcassegrain reducer lens is generally usable with most 2 star diagonals, although longer focal length and wide field eyepieces may vignette at the edge of the field. Delving deep into the mechanics of lens design, optics legend warren j. Lens design fundamentals by rudolf kingslake academic press, 1978 covers fundamentals needed by working designers. The chosen lens is a petzval lens with field flattener described in fundamental optical design, by m. Lens design fundamentals, kingslake, rudolf, johnson, r. But for a more normal budget, refracting telescopes start to overtake slr lenses in price to performance terms beyond about the 300400 mm focal length level.
Unlike the first edition, which was more a collection of lens designs for use in larger projects, the 2nd edition of modern lens design is an optical howto. Their very short focal length and small aperture lenses have enormous depthoffield almost nothing is out of focus. The flattening or compression effect is not caused by a particular kind of lens, it applies to all lens in the same way. The design process of fresnel lens was performed using matlab program. Field flattener lenses in binoculars improve edge sharpness. Triplet design lens will not degrade the performance of your flt.
The ffedapo01 is designed to work with explore scientifics achromatic doublet series dar,essential series and fcd100 series telescopes with diameters of 80 mm, 102 mm and 127 mm. Ff has a widespaced two lens design that corrects abberations most efficiently. Design, assembly, and testing of an objective lens for a free. Browse the amazon editors picks for the best books of 2019, featuring our. Agenas guide to focal reducers agena astroproducts. While advancements in the field over the past two centuries have done much to transform it from the former category to the latter, much of the lens design process remains encapsulated in the experience and knowledge of industry veterans. The best astrophotography telescope for a beginner my top 5. Ray tracing technique has been used to optimize the structure of lens using lighttools tm software. Does anyone own one and can tell me what benefits i should get. Designing large, highefficiency, highnumerical aperture. I was very impressed by both brands and i wasnt harassed by a salesman. The key decision factor is the cameratosubject distance. The left image shows a typical setup of the field flattener with f6 to f7. A fast camera lens or telescope essentially lets more light through to the sensor at once, and when shooting objects in the dark, thats a great option to have.
While most barlow lenses and focal extenders work with most kinds of telescopes available to amateur astronomers, focal reducers are designed to work in a narrow range. This flattener from takahashi is made as a universal replacement for fsfc flatteners. He deals with lens design software, primarily oslo, by far the current market leaders, and. Sensors ranging from apsc to fullframe are designed to match their lenses, which cover ranges from 2875mm equivalent, so image quality is topnotch. Buy lens design fundamentals book online at low prices in. The current version of dboptic offers polychromatic spot diagrams, imaging of extended objects and support for higher monitor screen resolution settings.
The tutorial demonstrates how to include a geometric sequence using the spherical general lens 3d part found in the comsol part library. As a short refractor owner at60ed f6, evoguide 50ed and also a c11 owner, ive been trying to learn more about field flattenerscorrectors. Countering the blurred effect typically rendered by the curvature of conventional lens elements, field flattener lenses help deliver a sharp, lowdistortion image across the entire field of view. The three aspherical lens elements, superud element, and ringtype usm all. The book begins with an outline of the general process before delving into aberrations, basic lens design forms, and optimization. This field flattener is designed to work with the altair astro 80mm f6 super ed triplet apo, and has an m48 rear thread adapter for connecting your dslr or ccd camera. In addition to reducing the mewlon focal length and focal ratio, this reducer also acts as a field flattener and corrector to reduce the coma inherent in the dallkirkham design as well as the curvature of field that put stars at the edge of the field subtly out of focus. As a result, any eyepiece will yield better off axis field correction. Designed to cover full size dslr cameras with clear lens aperture of 50mm. In this book, rudolf kingslake traces the historical development of the various types of lenses from daguerres invention of photography in 1839 through lenses commonly used today. She has written all editions of digital photography for dummies as well as 40 guides to.
Rudolf kingslake is regarded as the american father of lens design. Micronano lithography 27 nanotechnology 19 optical design and engineering 229 optoelectronics and communications 52 remote sensing 33. Using lens bokeh as a design element photographer nj new. This revolutionary new william optics ff68ii adjustable flattener was made for 6 7. Im wondering whether or not to purchase a field flattener to use with my wo refractor and canon dslr. For example, a superwide field of view is achieved through superior optical design with a field flattener lens system that provides sharp and clear images all. Coverage of the many types of catadioptric systems is outstanding. Ideal for 35mm film, fullsize sensors and large ccd cameras. With the reducer, the field of view is 45 arc minutes in diameter.
Although the lenses get more specialized, the foundation of these lens designs is built on previous lens design forms. Elements of modern optical design by donald oshea wileyinterscience, 1985 excellent collegelevel text with good explanations and a practical orientation. Advanced lens design uci division of continuing education. A flat lens is a lens whose flat shape allows it to provide distortionfree imaging, potentially with arbitrarilylarge apertures. Thoroughly revised and expanded to reflect the substantial changes in the field since its publication in 1978 strong emphasis on how to effectively use software design packages, indispensable to todays lens designer many new lens design problems and examples ranging from simple lenses to complex. Field flattener lens is a type of lens used in modern binocular designs and in astronomic telescopes. Books we recommend for optical design opticalsoftware. The petzval lens is one design which has significant amount of field curvature. Improve your night sky views with these telescoping accessories. To meet these demands, lens designers developed more specific use cases for these systems. For versatile, imagestabilized operation and clear and bright 12x images look no further than canons 12x36 is iii image stabilized binocular.
In previous articles we could see how a fast 85mm can be used for shallow depthoffield to shoot nearly anywhere by melting away the background. Field flattener lenses counteract the petzval field curvature of an optical system. Each illustration defines the application, a drawing of the lens and rays, lens aberration and plots. Takahashis field flattener uses a two element design. Modern lens design, 2nd edition book oreilly media. Many new lens design problems and examples ranging from simple lenses to complex zoom lenses and mirror systems give insight for both the newcomer and specialist in the field rudolf kingslake is regarded as the american father of lens design. The simulation results have been shown that fresnel lens has a good optical property such asconcentration ratio is 2500x, fnumber 0. Lens paper definition of lens paper by merriamwebster. Smith reveals timetested methods for designing topquality lenses. In addition to reducing the mewlon focal length and focal ratio, this reducer also acts as a field flattener and corrector to reduce the coma inherent in the dallkirkham design as well as the curvature. The oblique trace was performed for an object at infinity, 1.
Theory is limited to a minimum, and used to support the practical design work. The term is also used to refer to other lenses that provide a negative index of refraction. The process of designing lenses is both an art and a science. To overcome disadvantages of conventional fresnel lens we propose a novel technique to design fresnel lens. Capturing books with a digital camera about project runeberg. Lens design fundamentals, second edition downloader book. Since wide aperture lenses are rare today, most contemporary. Next to the flattener is an m48 extension tube to get the proper distance. The beam from a laser operating in the tem 00 mode typically has a diameter of only 1 or 2 mm and a gaussian amplitude profile. This field flattener is an excellent choice for cameras with cropped sensors apsc and smaller.
In this paper, we will show a design approach that makes full lens simulation and pillarbypillar optimization feasible, even on a desktop computer. Field guide to lens design 2012 bentley publications. Telephoto lenses typically have very little or no visible field curvature. It adds impressive building blocks to the foundation established by a. Field guide to lens design spie press field guide fg27. Lens design fundamentals, second edition, is the most comprehensive treatise to be published on the subject of lens design. Land and lens photographers envision the environment. It teaches how a satisfactory design can be obtained in a straightforward way. The book walks the reader through the lens design process using the traditional and. The wide angles from the focal length of this lens are bound to impress even professional photographers with an equivalency to a 1635mm zoom. The 10x20 is binoculars uses a field flattening lens element to provide edgetoedge sharpness for vivid images. Lens design fundamentals ebook by rudolf kingslake. With rubberguard armoring encasing the magnesiumaluminum alloy chassis, the phenom ed is an incredibly durable and lightweight binocular. It also aids handeye coordination, and the perception of the self within the environment.
Guiding is also easier, as offaxis guide stars are up to twice as bright due to their tighter infocus images. Explore scientific 2 field flattener ffedapo01 explore. The bokeh is a reference to how the quality of the background blur is rendered by a lens. Combination of apo140 with ff gives highly corrected field with round spot under 15mk in diameter over entire field 6x7cm pentax 67.
Telescope engineering apo140ed prime focus field flattener. Highquality tmb designed field flattener optimised for the flt98, flt110 and flt2 apo refractors. The factor that affects flattening is the distance from the camera to the subjects. Since the function of this field lens is to flatten the image in the field, it is called a field flattener. Lenses of short focal lengths ultra wide, wide and normal below 50 mm typically suffer more from field curvature. Taken in total, it is an optical design book, but written in such a way that amateur astronomers will find it of value whatever their level of interest, and the person seriously interested in design will find it a godsend. Lens design fundamentals by rudolf kingslake overdrive. Over the years we have found a number of books to be very useful, so we hope that you will benefit from these. Deep sky astrophotography dslr primer what youll need. However, bokeh is virtually irrelevant for the tens of millions of very small sensor smartphone and digital pointandshoot cameras sold every year. Excerpt from optical design fundamentals for infrared systems, second edition. Clinical anomalies pose a wide range of problems to the sufferer, but normal binocular operation must first be understood before the eye specialist can. This was the telescope that allowed me to capture my first longexposure deepsky images including the orion nebula, north america nebula, and the great andromeda galaxy. Buy lens design fundamentals book online at best prices in india on.
This selection guide is intended to help develop an understanding of the basic information required to select the proper lens. Eyepieces longer than 35mm in focal length are not recommended for use with a reducer lens. The teleskop service flattener has easy adaption fits directly into the 2 focuser. Each groove of fresnel lens focus bundle of parallel rays to focal point p ng, then the bundle of light has been distributed over receiver with uniform. The extension tube is available in several different lengths. Telescope optics, a comprehensive manual for amateur. All phenom ed field flattened binoculars are backed by our diamondtuff lifetime guarantee. Stm coated with an excellent doublet air spaced design. From an early lens still being manufactured for use in lowcost cameras to designs made possible through such innovations as lens. Robert correll is author of digital slr photography allinone for dummies as well as books on other canon dslr models, sony cameras, hdr photography, and photo restoration. William optics tmb field flattener for flt first light. Many new lens design problems and examples ranging from simple lenses to complex zoom lenses and mirror systems give insight for both the newcomer and specialist in the field. Canon 10x20 is series weather resistant porro prism is. Page 1 of 2 field flattener lenses posted in binoculars.
Dec 26, 2004 any macro lens is fine, or a normal lens with a high quality twoelement closeup lens attached. It increases the effective focal ratio of the objective. The concentric schwarzschild objective with field flattener. As lens design forms evolve, the lens use cases get more and more specialized. Specifying the right lens for any video application is critical to configuring an effective system.
With the 50 mm lens, the camera needs to be close to the book and the threedimensional perspective is skewed. Manuals downloads tec field flattener ff has been designed for correcting field curvature and offaxis astigmatism of the apo140. Received a distinguished instructor award in 20 for his teachings in lens design at uci division of continuing education. Lens design fundamentals engineering textbooks elsevier. I havent yet found basic info on how field flatteners are designed so i thought id see if knowledgeable people here on cn could provide some basics. Lens paper definition is a soft nonabrasive lintless tissue paper used for wiping and wrapping lenses. Canon 12x36 is iii image stabilized binocular 9526b002. Field flattener lenses counteract the petzval field curvaturepetzval field. This teleskop service flattener was designed for 6 16 gso rcs. At the top and bottom, the books back cover is shadowed by the page in view. Meades focal reducerfield flattener is a fully multicoated, 3 element design to help the astrophotographer capture wide field photographs of the night sky with the series 6000 apos. The basic idea of the fresnel lens for the 2d cpv system is depicted in figure 1b. The two photos below were both taken with a nikon d200 using an aperture of f8.
Ts universal 2inch field flattener for refractors from f. Field flattener lens is a type of lens used in modern binocular designs e. A novel technique to design flat fresnel lens with uniform. The treatise contains over 280 proven designs from patents and other writings. A course in lens design is an instruction in the design of imageforming optical systems. Oct 22, 2019 the relatively compact size has this lens weighing 0. Theres another aspect to this the bokeh of the lens. When a lens is focused on a flat subject, the light rays from the subject will converge some distance behind the lens, at the focal point. I spent a generous amount of time looking through some highend zeiss and swarovski binoculars. The book introduces geometrical optics, optical instruments and aberrations. The explore scientific ed80 is a superb telescope for astrophotography. Field flatteners and dslr photography discussions cameras. In best form lenses the lens shape is also required to minimize the aberration also reduce effect of spherical and other aberration. I started a post a couple of days ago in which i spoke of taking a trip to my local cabelas.
Modified pinhole spatial filter producing a clean flat. Lens design fundamentals edition 2 by rudolf kingslake, r. Field flattener lenses in binoculars improve edge sharpness and lower the distortion. It will not provide a flat field when used with fullframe cameras. May 09, 2014 deep meniscus lenses a with a base curve of 6.
Julie adair king is a veteran photography professional and instructor with more than 60 books to her credit. This book holds a unique place in the optics literature. Feb 14, 2012 the fixed lens camera market may be a bit niche, but its here that youll find some of the best cameras you can buy. The second lens has completely cancelled the petzval curvature of the first lens, while leaving virtually all of its optical focusing power intact. Actually, this property of lenses applies to our own eyes as well. This is often called a field flattener lens, and is a very common approach to fixing up field curvature problems. Conrady in applied optics and optical design and rudolph kingslake in lens design fundamentals, first edition. Field guide to lens design spie press field guide fg27 field.