The answer lies at the nexus of objective science, an enduring passion for excellence, and a lineage of inspired optical designers steeped in a great tradition.
By Jason Schneider
Many years ago at Photokina, I had the distinct pleasure of meeting and talking for the first time with Peter Karbe, the Chief Optical Designer at Leica since 2002, and world renowned leader of the team that created so many of the superlative lenses in the current Leica panoply. Modest, soft-spoken, and supremely knowledgeable about his favorite subject, he’s just the kind of unassuming gentleman you’d expect in his role—indeed, his demeanor somewhat reminded me of the late, great Rudolf Kingslake (1903-2003), longtime Chief Optical Designer at Kodak, whom I met at the offices of Popular Photography in the ‘80s.
Not surprisingly, Karbe and I chatted about lenses, and in particular the 50mm f/1.4 Summilux-M ASPH, the best of its kind ever made according to Pop Photo’s then-recent MTF tests. I expected to learn a bit about the knotty optical problems he had solved to create this masterpiece, but before he began explaining what he did, he paid heartfelt homage to the high-speed 50mm lenses designed by his late predecessor, the great Dr. Walter Mandler. He expatiated at length, revealing that he didn’t start out with a clean sheet of paper, but was operating within a great tradition with the goal of bringing it to the next level. He didn’t belittle his contributions, but he truly believed he was standing on the shoulders of giants, and was dedicated to refining and embellishing their noble accomplishments. In an instant I knew I had discovered the secret of what makes Leica lenses so special and why they’re designed primarily to capture beautifully rendered images, not merely to ace lens tests. Peter Karbe though clearly a master at applying the latest computer-aided-design (CAD) techniques, designs lenses that are essentially works of art. They must not only fulfill stringent performance criteria, but also embody a great heritage in what they are and what they do.
Let’s take a brief excursion into the Leica Lens Tradition as embodied in the achievements of two of Peter Karbe’s illustrious predecessors, the renowned optical designers, Max Berek and Walter Mandler.`
Max Berek: The genius behind the Elmar, Summar, and Summitar
Max Berek (1886-1949) was a German mineralogist, mathematician and optical designer acclaimed for his work in polarization microscopy and as the designer of 20 Leica lenses, including some of the earliest ones that were instrumental in positioning Leitz as a leading maker of camera lenses, and in establishing the 35mm format as a viable system. His most famous creation was the 4-element, 3-group 50mm f/3.5 Leitz Elmar that debuted on the Leica I in 1926. Although the design resembles the Zeiss Tessar, it was actually derived from Berek’s original 5-element, 3-group 50mm f/3.5 Leitz Anastigmat (later labeled Elmax in his honor) that was fitted to the first run of Leica I cameras released in 1925. The 50mm f/3.5 Elmar endured as a mainstay in the Leica line for over 50 years and was recalculated with rare earth glass elements, to create the esteemed 50mm f/2.8 Elmar (1957-2007) that was offered in LTM screw and M-mount versions.
Berek also designed Leica’s first high-speed normal lens, the 6-element, 3-group 50mm f/2.5 Leitz Hektor (1930-1936), the landmark double Gauss formula 6-element 4-group 50mm f/2 Leitz Summar (1933-1940), considered one of the first great high-speed normal lenses, the long-lived 135mm f/4.5 Hektor telephoto (1933), and the fine-performing 7-element, 4-group 50mm f/2 Leitz Summitar (1939-1955, coated after 1946), that upheld Leica’s reputation for optical excellence until the arrival of the breakthrough 50mm f/2 Summicron of 1953, which set a new world standard in optical performance. Berek joined E. Leitz Wetzlar in 1912, one year after Oskar Barnack, and he not only helped Barnack realize his vision by computing the designs of the first Leica lenses, he was also a pioneer in developing lens coatings. Understandably, Berek’s vintage designs do not deliver the awesome sharpness and contrast of modern lenses, especially at their widest apertures, but all are still capable of rendering beautiful, detailed images. Because of his refusal to comply with certain demands of the Nazi regime, Berek was stripped of his university professorship in the early ‘40s, and only reinstated in 1946, three years before his death.
Here’s a quote from an interview with Berek in 1949 that reveals a lot about Leica:
Q: What certainly does the buyer have of obtaining a perfect lens?
Berek: We do not have the ability to create images totally without faults. In this sense there are no perfect lenses. The problem is to correct the mistakes so that, in view of the practical application of the lens, it can be considered perfect. Everything depends on tolerances; they must be so close that the remaining errors will have no influence. That is assured by a production system thought out to the smallest detail, one that covers the entire creation of a lens. It starts right at the cutting of raw pieces of glass by controlling impurities, stress lines, etc. This control increases during the manufacture of each single element, while shaping it by grinding, while polishing and mounting it, and combining it with the rest of the optical system. When the lens to be finally passes all tests prescribed during the individual working steps, it still won’t be delivered, but will be tried for critical test exposures. Thus the buyer in each case will have the assurance of getting a perfect lens.
When it comes to memorializing Max Berek, nobody said it better than noted Leica historian Erwin Puts on the 50th anniversary of Berek’s death on 15 October 1999:
“Max Berek is a designer with the modesty that characterizes true genius, and the results to prove his genius. He wrote only a few books about optical design and microscopy, but these were and are decisive in his craft. Even today the perceptions and views of Berek about lens design and aberration corrections can be found in every Leica lens, even recent ones. The current staff of Leica designers still refers to his books and views for inspiration and guidance. Berek was a truly great person and it is a bit tragic that we all use today’s Leica lenses without even realizing his great contribution to their superb image quality.”
Walter Mandler (1922-2005): Inspiration and tradition meet computer-aided design
Walter Mandler, son of a German farmer, joined E. Leitz Wetzlar in 1947 and worked with Max Berek as a lens designer while also studying physics at Giessen University. He earned a bachelor’s degree at Giessen, and eventually (in 1979) a Ph.D., graduating Summa Cum Laude. In 1952, when Leitz inaugurated Ernst Leitz Canada (ELCAN) in Midland, Ontario, Mandler was a member of the Wetzlar team “temporarily on loan” to help establish the new branch. He wound up staying in Canada for more than 50 years, and became a Canadian citizen.
Maddler’s main contribution to optical engineering was his pioneering work in applying computer-aided design to what had long been an intuitive, seat-of-the pants profession largely based on longstanding tradition and informed hunches augmented by mountains of tedious calculations. The Midland operation was a perfect place for him to develop his immense talents and refine his ingenious designs because it specialized in researching retro-focus wide-angles, apochromatic lenses, and ultra-high-speed designs, many employing exotic types of glass specially made for Leitz by Schott and Corning. Mandler was a master at optimizing Double-Gauss designs using a computer, a methodology detailed in his doctoral dissertation. He became vice president of ELCAN in 1974 until his retirement in 1985.
During his long tenure, Walter Mandler designed more than 45 high-performance lenses for Leica rangefinder (M) and SLR (R) cameras, many of which are still considered classics. Mandler’s treatise on Double-Gauss designs (1979) is still considered the definitive analysis on the limits and potential of this important class of lenses. Because he was a master at balancing the crucial factors of performance, cost, and ease of manufacture many of his designs remaned in production for decades. Here are 3 notable examples:
50mm f/1 Noctilux-M: The fastest lens in the Leica M system for over 30 years (1976-2008) this advanced 7-element, 6-group Double-Gauss-formula lens set a new standard in super-speed normal lenses at the time, and was superseded only when the landmark 50mm f/0.95 ASPH Noctilux-M designed by Peter Karbe was unveiled in 2008. It had a 10-bladed diaphragm with click-stops at half-stop intervals, and 17,535 examples were made from 1975-2005. Walter Mandler and Gerhardt Bechmann (1970) are listed jointly as the designers.
50mm f/2 Summicron R I: This classic 6-element, 5-group Double-Gauss lens was the mainstay of Leicaflex/ Leica R shooters for over a decade and its impressive sharpness and beautiful rendition helped to promote Leica’s 35mm SLRs as serious contenders in the upscale/pro category. It had a 6-bladed diaphragm, focused to 19.7 inches, and weighed in at a hefty 1.5 pounds. According to the official stats, Leitz made 95,647 of these superlative lenses between 1963 and 1975.
75mm f/1.4 Summilux-M: Based on his second version of the 50mm f/1.4 Summilux-M that was in production for more than 40 years (1961-2004) this brilliant 7-element, 5-group super-speed moderate telephoto was Mandler’s personal favorite. It’s quite sharp even wide open, has beautiful rendition, focuses down to 29.5 inches (1:8) for impressive headshots, and was made in Canada. Listed in the catalog from 1980-2007, total production ran to 14,752 units.
Peter Karbe said it best in this heartfelt tribute written just after Mandler’s death:
“I can readily say that Dr. Mandler was one of the great optical designers at Leitz and that his work constituted a major contribution to the success of the Leica M rangefinder camera. Dr. Mandler was clearly ahead of his times with his developments. That is proven by the numerous optical computations that still have lost nothing in terms of current relevance. Among them is the 50 mm f/1 Noctilux-M lens that he designed. Today, many publications still refer to his work, notably the landmark 50 mm f/2 Summicron-M lens. And there are numerous other examples that prove how important his work was for the evolution of photographic optics in general and for the evolution of photography at Leitz. This includes his apochromatically corrected telephoto lenses… While I was writing these lines, it occurred to me that that I am not qualified to render a judgment of Dr. Mandler.”