Leica M-Lenses
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Leica M-Lenses Their soul and secrets by Erwin Puts September 2 0 0 2 Introduction Secrets revealed It is well known that Leica M lenses, in spite of factual explanations, he also presents charts and their compact design, deliver imaging performance measurement curves that have never before been with the highest quality. But what are the reasons published in this form. Guidelines for interpreting behind the fact that, over the many years that new these tables and curves make these graphics even Leica M lenses have been computed, designed more practical. and produced in an ongoing succession, additional improvements still continue to be achieved? These Erwin Puts has been making photographs since improvements, in the opinions of the advertising 1960 and he explored the technical aspects of experts at Leica, leave all previous advances far photography even while he was studying business behind. administration. The author has been working with Leica since 1989, and in a series of more than 30 In this brochure, Dutch photojournalist Erwin Puts articles published around the world since 1992, he explains the principles on which the secrets of discusses the history, technology and the Leica M lenses are based and how the extensive operation of Leica cameras and lenses. The core of knowhow and the great competence of Leica his work consists of lens test reports that are optical designers succeed again and again in conducted with a meticulous thoroughness that is achieving ever higher peaks in maximum recognized by his competitors. The work brings performance in their optical systems. together optical parameters and practical applications, clarifying the limits of performance The author also pays special attention to the capability, with proper attention to their interplay popular concern expressed by numerous Leica with the different types of film materials. users, who wonder whether the „old“ lenses are superior to current Leica M lenses in terms of For many readers, this brochure will reveal many contrast range, contour sharpness and resolving a secret, thus clarifying the reasons for the power. With his knowhow and the experience of performance characteristics of Leica M lenses. We numerous test series, he juxtaposes comparable wish you much enjoyment in reading this lenses and their performances. In addition to brochure! Leica Camera AG Ralph Hagenauer Marketing Communication Leica M Lenses [1] Contents [2] Leica M Lenses Contents Introduction 1 The Soul of Leica M-Lenses 4 Core Technologies 12 Contents MTF Analysis: those shapely curves 15 Color Rendition 19 21mm Lenses 20 21mm f/2,8 Elmarit-M 24 21mm f/2,8 Elmarit-M ASPH 25 24mm Lenses 26 24mm f/2,8 Elmarit-M ASPH 29 28mm Lenses 30 28mm f/2,8 Elmarit-M (1979) 32 28mm f/2,8 Elmarit-M (1993) 33 35mm Lenses 34 35mm f/1,4 Summilux-M 37 35mm f/1,4 Summilux-M aspherical 38 35mm f/1,4 Summilux-M ASPH 39 35mm f/2,0 Summicron-M 40 35mm f/2,0 Summicron-M ASPH 41 50mm Lenses 42 50mm f/2,8 Elmar 46 50mm f/2,8 Elmar-M 47 50mm f/2,0 Summicron-M 48 50mm f/2,0 Summicron-M (current) 49 50mm f/1,4 Summilux 50 50mm f/1,4 Summilux-M 51 50mm f/1,2 Noctilux 52 50mm f/1,0 Noctilux-M 53 Tri Elmar-m 1:4/28-35-50 mm ASPH 54 28mm f/4,0 56 35mm f/4,0 57 50mm f/4,0 58 75mm Lenses 60 85mm f/1,5 Summarex-M 62 75mm f/1,4 Summilux-M 63 90mm Lenses 64 90mm f/2,8 Tele Elmarit-M 68 90mm f/2,8 Elmarit-M 69 90mm f/2,0 Summicron-M 70 90mm f/2,0 APO Summicron-M ASPH 71 135mm Lenses 72 135mm f/4,0 Elmar-M 74 135mm f/2,8 Elmarit-M 75 135mm f/3,4 Apo Telyt-M 76 Glossary 78 Leica M Lenses [3] The Soul of Leica The soul of Leica M lenses Ever since Professor Max Berek de- specifications nearly without human in- have been achieved without a good signed his first lens for the Leica, the 50 tervention or control. measure of intuitive creativity. mm f/3.5 Anastigmat/Elmax, in 1924, The likelihood that a design generated In order to understand this soul that is the optical capabilities of Leica lenses in that manner is an ideal solution for present in every Leica lens, let us take a have been intensively analyzed and dis- the intended purpose is about one in a brief look at computation techniques, de- cussed. Some reviewers state that billion. And that is the reason why the sign procedures and optical evaluation Leica lenses are the standard against creativity of the designer is essential, techniques. After this small “tour de which others are to be judged. Others even decisive for creating an optical sys- force” we will be able to sense and ap- expressed the opinion that, even though tem that has optimal performance. preciate the “Leica spirit in the glass”. Leica lenses perform very well, they are It might seem strange that I wish to basically as good as the products of draw attention to the importance of the Let us begin with a basic explanation. other manufacturers. Leica lenses are creativity and the art of the lens de- If we take a simple lens, for instance also said to have a special kind of im- signer as an important factor in optical the good old burning glass, to create an age-recording quality that is often com- design. image of the sun on a piece of paper, pared with three-dimensional rendition The fundamentals of modern optical the sun is rendered as a very bright spot or with pictures that convey a three-di- design are rooted in mathematical and and the paper begins to burn because mensional impression. This peculiar physical theories. The widespread appli- the lens causes the sun’s energy to “optical fingerprint” is frequently dis- cation of computer-assisted design me- concentrate in one point. In early times, cussed among Leica aficionados and thods by all manufacturers has fostered a single lens element was the only collectors. Sometimes it is even claimed the impression that lens design nowa- means of obtaining an image. For very that older Leica lenses have certain days is a highly automated process. small angles of view, like those of a tel- mythical qualities that gradually disap- Leitz was one of the very first optical escope, for instance, one was satisfied peared in newer lenses that were de- manufacturers to use computers to ac- with such an image. Louis Jacques signed later. Then the fact is brought up celerate the extensive and laborious cal- Mandé Daguerre, who made his very that optical design is being performed culations of ray tracing significantly. first photograph in 1839, needed a con- more and more by computers, so that That was around 1955. Today the soft- siderably larger angle of view for his im- the personal “fingerprint” of the de- ware programs used by the “Optisches age plate. The image created by a single signer is no longer as evident as it once Rechenbüro” (optical design depart- lens element was quite sharp in the was. ment) are highly refined proprietary al- center, but very blurred along the peri- It is undoubtedly true that Leica lenses gorithms. Even so, current high per- phery. At that time, optical aberrations had and have particular characteristics formance optical systems could not were still unknown and better solutions and qualities that are the very reason for the fascination and the challenge of working with these lenses. In my opin- ion, the question whether a photograph- er always achieves the best results when he or she uses a Leica lens is quite unproductive. Every lens has a large number of specific qualitites and it is highly unlikely that every one of these qualities will always be of the highest degree. Behind every Leica lens one can sense a passionate determination to control and to eliminate the geometrical aber- rations that are present in every optical system. It is true, of course that con- temporary manufacturers of optical products can no longer operate without using sophisticated computer installa- tions. It is a fact that modern computer programs can produce new optical de- signs in accordance with prescribed [4] Leica M Lenses The Soul of Leica could only be found by means of experi- experimental methods was Joseph together cause unsharpness and distor- mentation. The phenomenon of the dis- Petzval. And his portrait lens was clearly tions in the image. persion of white light into various spec- superior to lenses that had been cob- In principle, the next step is still easy. tral colors had been known for a long bled together experimentally. Although Now that we know, at least theoretical- time, but now it became a problem in now it was possible to use formulas to ly, what causes the unsharpnesses in making Daguerreotypes. The photo- trace rays quantitatively, the knowledge an image, all we need to do next is to graphic plate was sensitive to blue light, was still lacking as to why the rays were correct these aberrations. And this is but the human eye is more sensitive to bent in this manner and why they did precisely where the creativity of the op- yellow light. That is why it was possible not reach the ideal or the theoretical lo- tical designer comes in. to use a simple lens element to focus cation of the image point.