Camera lens basics helpful guide to understanding camera lenses. Shortfocus, wideangle lenses are usually mounted near the film. Dec 30, 2014 wideangle lenses also share at least two design challenges. Smith, and optical system design robert fischer, introduction to lens design. It becomes clear that size is a very tight requirement and standard lens design solutions are not suf. Design of optical relay systems lens design opti 517 jose sasian college of optical sciences university of arizona tucson, arizona 85721 usa.
The percival philosophy is similar to that used in modern spectacle lens design. But to do so, the physics and elements inside the lens need be to. A lcos miniprojection lens which has the advantages of small semidiameter, total track of lens in 80mm, field of view of 72, projection screen up to 28, and the. Design of optical relay systems university of arizona. Design for near and distant viewing distances is essentially identical. But the not all the lens designs are simple lenses, we will look at newer and important lens design forms as well.
The popularity of this lens design made the name retrofocus synonymous with this type of lens. The mounting flange on an hasselblad is about 79mm from the film plane. Basically, the objective of a retrofocus lens has the effect of a negative element. By the late 1920s, taylor hobson had become arguably the top developer of motionpicture lenses, and had developed the reverse telephoto lens for small 8mm movie cameras. Lens l2 is a first negative meniscus and lens l3 is a second negative meniscus, and both of the convex surfaces of these lenses l2 and l3 are directed to an object.
In practice, retrofocus design is a matter of degree rather than kind. Mouroulis mcdonald geometrical optics and optical design, oxford, 1997 3. Lens design, gives insight into the engineering problems of each lens design type and practical solutions that are expensive to discover independently. This is an ultimate guide of lens design forms, the optical systems that are used in our world. Retrofocus lens is a reversed telephoto lens in which the front element is negative, moving the rear nodal plane from which the focal length is measured behind the rear of the lens. Since i started shooting with rangefinder 35mm film cameras, i noticed a very different look to my wide angle images. Optical system classification summer term 2012 herbert gross 1. Lens design field guide to julie bentley craig olson spie field guides volume fg27 john e. Reversed telephoto retrofocus and fisheye lenses 395. For example, all of the lens designs in the first edition of mld plus many others are included in the lens libraries of the optical design program oslo a product of lambda research corp. Greivenkamp, series editor bellingham, washington usa ffg27 covers and dd 3 g 2 7 co ve rs a n d title.
An interesting new wideangle lens type is a fourcomponent form found commonly on the socalled compact 35mm cameras. An optical designer can create the best lens in the world, but when it is too big, too expensive or too complex it will not go into production. Slrs must use retrofocus designs so that the mirror can clear the back of the lens. Back in the 1930s, the bio in biogon didnt refer to biology as it would commonly today. Updated for 2019, this guide on camera lenses will give you camera lens basics, do a comparison of lens focal lengths, cover the different types of lenses, as well as help you choose the right lens to use with different kinds of photography. Figure 1 three typical optical design solutions for ccms from the patent literature. Finally, according to design index of the lcos miniprojection lens, a u. Retrofocus lenses cost more to make than lenses of normal construction. Besides having the excellent telecentricity vital in lenses for digital cameras, this retrofocus lens has many other advantages. Projection displays based upon reflective liquid crystal light valves spatial light modulators require dichroic beam splitters. This is typically required in an slr camera, to allow space for the swinging reflex mirror. Us5597222a optical relay lens system for projection.
Zeiss wide angle lenses all share the common gon ending, which is derived from the greek word gonia meaning angle. Wideangle and sometimes normalfocus lenses for such cameras therefore use retrofocus designs. A comprehensive guide to camera lens design and zeiss. A wide angle retrofocus lens system consists of seven lenses l1 through l7.
Most standard range zooms even today keep that pattern. A diffractionlimited baseline lens design and a second design with two fewer lens elements are modeled and their fullsystem imaging performance is simulated. First and foremost, a piece of glass that is flat on both sides is not a lens it is a window. Retrofocus lenses are designed to be positioned farther from the filmsensor plane in order to leave room for an slrs reflex mirror.
The design used for lf lenses probably gives better optical quality. Institute of photonic system, national chiao tung university, tainan city 71150, taiwan 3. Natural and optical vignetting lead to a gradual transition. Division of gastroenterology and hepatology, chi mei medical center, tainan 71004, taiwan 2. 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. Simple lenses are lenses consisting of a single element. Zebase 6 includes a copy of milton laikins book, lens design. Page 18 the construction of the special design lens glassmold aspherical lens the dp2s integral lens is of the retrofocus type.
This is achieved by incorporating a special lens group known as a telephoto group that extends the light path to create a longfocus lens in a much shorter overall design. It is the standard design for wideangle and fisheye lenses in slr and cine cameras where a conventional lens would foul the shutter mechanism. With a wideangle lens, the focal length is significantly shorter than the diagonal of the picture format. Special correction features i 20161207 herbert gross winter term 2016. Retrofocus design also influenced non retrofocus lenses. Design and fabrication of lowcost thermal imaging optics.
Reflective 28 singlets 29 achromaticdoublets 30 airspaceddoublets 31 cooketriplet 32 doublegauss 33 petzval lens 34 telephotolenses 35 retrofocus andwideanglelenses 36 refractive versus reflective systems 37 obscurations 38 newtonianandcassegrain 39 fifj. Our first interaction with optics is usually the introduction of snells law. The process of designing lenses is both an art and a science. The introduction of the computer revolutionized the way lenses optical systems are designed and evaluated.
Dont think that smallformat lenses dont have falloff just because center filters are almost never used in these formats. Moreover, the dif ferent lens types that are described are used for applications ranging from 8mm video to 6 3 9cm roll. It is the standard design for wideangle and fisheye lenses in slr and cine cameras where a conventional lens. Single lens reflex cameras need a certain minimum lens tofilm distance to accommodate the swinging mirror. The angenieux retrofocus photographic lens is a wideangle lens design that uses an inverted telephoto configuration. Finally the elements in a retrofocus lens tend to be larger, making manufacturing and mounting slightly easier. Designing a lens for flangetofilm distance approximately equal to focal length this is called normal construction, not to be confused with focal length normal for a format is easier than designing for flangetofilm distance much longer than focal length. The top design is an asymmetrical retrofocus lens for contax slr cameras and all that to give way to the mirror. Sep 19, 2012 secondly, leica lenses arent retrofocus lenses. Looking at the complex designs of modern zooms, it can be somewhat difficult to see their heritage, but sometimes you can.
Telephoto lens design allows the lens to be considerably more compact by moving the principal planes out in front of the lens. With practical zemax examples joseph geary, are all great books, just to name a few. Reversed telephoto retrofocus and fisheye lenses 395 14. Smith reveals timetested methods for designing topquality lenses.
Another program, lensview by brian caldwell, is a compilation of more than 30,000 lens designs and patents. Retrofocus refers to a type of lens design, pioneered and originally trademarked by pierre angenieux in the early 1950s, which permits a short lens optical focal length while providing a greater back focus distance. Wideangle lenses also share at least two design challenges. The zeiss distagon t 2,815 zm is a fast lens for its focal length, allowing for handheld photography under difficult lighting conditions. The retrofocus arrangement is formed by a front negative. The ultimate guide to lens design using the classic. A retrofocus type lens system comprising a first lens group having a negative refracting power and a second lens group having a positive refracting power in the order named from an object side, wherein said second lens group is constituted by a front group having a positive refracting power and a rear group which has a positive refracting power and is movable along an optical axis to. The retro focus design allows a short focal length lens to accommodate the flangefocal distance of typical slrs, retaining infinity focus. Application of computational imaging to wide field of view.
Lee of the taylor hobson company, the same folks who produced the cooke triplet lens, which was perhaps the most significant lens ever made. The optical system is composed of 4 pieces of lenses, including two single lenses and one cemented doublet. Malacara malacara handbook of lens design, dekker, 20 5. 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.
On the flip side retrofocus lenses suffer from higher distortions and and tend to more complex distortions which are harder to correct. Panoramic annular lens design of endoscope request pdf. Today, you can purchase distortionfree retrofocus ultra wideangle lenses as wide as 14mm 114 aov and as fast as f2. Sep, 2011 the lens also has a bit of a retrofocus design with a negative element in front and a positive group near the rear in yellow. Jun 11, 2010 in practice, retrofocus design is a matter of degree rather than kind. Vignetting carnegie mellon school of computer science. The use of the zoom by lelouch almost became a symbol of the new wave. Super wideanglelenses are those with focal lengths between the length of the short side of the format and half the diagonal. This lens is characterized by a triplet construction followed by a rear element that is strongly meniscusshaped, convex to the image plane.
Lenses in this section may overlap with lens designs in other sections, for example the wollaston landscape lens is a single element and also a camera lens design. The zeiss distagon t 2,815 zm is the pinnacle of modern, rectilinear rangefinder lens design, offering very dynamic perspective effects for critical architecture and interior photography. Lens extrem wide angle fish eye retrofocus ii vivitar wide angle retrofocus distagon slr flektogon retrofocus plasmat kinoplasmat ultran noctilux quadruplets double gauss. Zebase 6 is a collection of over 600 sequential optical designs in opticstudio format on cd. Lens design fundamentals rudolf kingslake, applied optics and optical design part 1 and part 2 a. Retrofocus lenses are generally confined to the short focal length slr lenses typically less than about 50 mm. Overview introduction relays for freespace photonic switching relays for microlithography relays for periscope systems. The basic lens design forms are in here, and we can take a deep look into the development of lens design. The lens also has a bit of a retrofocus design with a negative element in front and a positive group near the rear in yellow. Equivalent performance between the two systems, each with three aspheric surfaces, is achieved by optimizing the.
Before we can begin to design a lens for an application we must understand what a lens does and a little bit about how the lens is made. Field guide to lens design 2012 bentley publications. The next article will cover aberrations in relative depth. But to do so, the physics and elements inside the lens need be to completely different, and larger. The types of optical systems in a lens designers toolbox. Dual view capsule endoscopic lens design mingjen sheu,1,7 chewen chiang,2 wenshing sun,3 jhijoung wang,4,5 and juiwen pan2,5,6 1. Home ebooks field guide to lens design retrofocus and wideangle lenses translator disclaimer you have requested a machine translation of selected content from our databases. A telephoto lens, in photography and cinematography, is a specific type of a longfocus lens in which the physical length of the lens is shorter than the focal length. Another more recent example of this lens is a lens design by miyazakisan, of msoptical, the aporis 5mm f2. Modern lens design, 2nd edition book oreilly media. Consequently any lens with a nominal focal length less than about 120mm is likely to be a retrofocus lens to some degree. Historically, the retrofocus lens is a relatively new design. A later article will explore historical design forms such as the doublegauss, retrofocus, or sonar forms and touch base on why they are used, their pitfalls, and their strengths. Telephoto lenses have positive lenses in the front of the lens and negative lenses in the rear of the lens.
Most of the worlds fastest lenses today are derivatives of the planar design, including. Nonretrofocus wideangle lenses were manufactured for a relatively short period before newer retrofocus design wideangle and ultrawideangle lenses began coming to market. Kingslake lens design fundamentals, spie press, 2010 2. Practical computeraided lens design by gregory hallock smith. Design and study of lcos miniprojection lens based on zemax. Our solution is a 2element design in the inverted telephoto or retrofocus configuration. This is accomplished in the opposite way from retrofocus lenses. M42 angenieux retrofocus lens image by woradate pattayawan image rights retrofocus refers to a type of lens design, pioneered and originally trademarked by pierre angenieux in the early 1950s, 1 which permits a short lens optical focal length while providing a greater back focus distance. Lens l1 is a positive meniscus with its convex surface directed to an object. Delving deep into the mechanics of lens design, optics legend warren j. Non retrofocus wideangle lenses were manufactured for a relatively short period before newer retrofocus design wideangle and ultrawideangle lenses began coming to market.
The angenieux retrofocus for still cameras was introduced in france in 1950 by pierre angenieux. Especially when using wa lenses with a more symmetrical design with the rear element deep into lens mount, like the zeiss 35mm f2. The angle of view and other effects of longfocus lenses. First is the obliqueness of angle the light rays hit the focal plane. If it is about the same as the long side of the format, the lens is considered to be a moderate wideangle lens. The black bars indicate the actual position of the variable. At that time there were not a lot of lenses that were as advanced and as high performing. Fischer tadicgaleb optical system design, mcgraw hill, 2000 4. However, the three lens types, distagon biogon and hologon also display major differences along with this common feature. This lens has much less astigmatism than either conventional triplets or tessars and can.
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