LEICA Barnack Berek Blog: PETER LOSERIES : A HISTORICAL WORLD-CLASS EXPERT IN LEICA CAMERAS SHUTTERS AND KEY FIGURE IN THE CREATION OF THE LEICA M6

Main Text and Captions of Leica Cameras and Lenses: José Manuel Serrano Esparza.

Peter Loseries photographed by Norman Goldberg in Wetzlar in 1984, year in which the Leica M6 was launched into market.

Courtesy of his son Don Goldberg. DAG Camera Repair.

Between mid sixties and late nineties of XX Century, Peter Loseries was a Leica reference-class figure in the scope of miniaturized mechanics and the designing of shutters for both rangefinder and reflex cameras.

An exceedingly brilliant Leitz engineer and designer, featuring tremendous knowledge, experience and a unique insight to solve the most difficult mechanical and technical challenges, Peter Loseries and Otto Domes ( an also Leitz great engineer)

improved to the utmost the mechanically controlled focal-plane shutter with horizontally travelling rubberized cloth curtains of the Leica M6, reaching the evolutive pinnacle of Leitz mechanical shutters of Leica M cameras after thirty years of progression in this sphere.

It was an amazing feat, because from 1954 onwards, the utterly new and mechanically controlled focal-plane shutters of Leica M cameras from M3 model onwards designed by Willi Stein, Dr. Ludwig Leitz and Friedrich Gath (in which the shutter speeds were formed by control cams and by a gear train as a delay mechanism, in addition to offering from 1957 a dial with uniform geometric calibration for the exposure times — unlike Barnack´s original shutter from 1924 in which shutter speeds were not calibrated in uniform intervals) were already extraordinary and very difficul to better.

As a matter of fact, even in 1954, thirty years before the launching into market of the Leica M6, the mechanical shutter of the Leica M3 (introduced at the Photokina Köln of that year) was exceptional and very reliable, because top priority was put on improving its travel cycle and solving the uneven exposures (particularly on using the fastest speeds, when the right side of the image received more light than the left one) brought about by the acceleration that took place when the slit set with the shutter speed dial (and which remained constant while it crossed the film gate) traversed the film gate.

It had meant a technical tour de force, which was solved by Ludwig Leitz´s brainstorm of letting the two shutter curtains travel in an independent way, to avoid limiting the slid width (as well as using accurate measures of the dynamic work stages to attain that the two successive edges of the shutter curtains kept identical time interval from each other at every spot on their way through the film gate), and the use of drive springs with very special metallic alloys was of invaluable help to get even exposures.

Therefore, the mechanically timed focal-plane shutters with horizontally travelling rubberized cloth curtains of the analogue Leica M6 (1984),

Leica M6 TTL (1998)

and MP (2003) rangefinder cameras,

Utterly mechanical shutter of the Leica M6 from 1984 (the apex of thirty years of continuous improvement since the introduction of the Leica M3 in 1954), on top left of the image, showing its complexity, with a lot of miniaturized gears, springs, levers, cams, bolts, etc. The internal very tiny mechanical components of this device were designed with extremely low manufacturing tolerances, something fundamental for the camera´s renowned reliability and almost imperceptible sound operation. Also visible are the curtains drum, the film spool, the take-up spool, the many spring and gears, the shutter speed dial (beside the accessory hot shoe), the shutter release button, the film advance lever (on top left of the image, next to the frame counter) and the rewind lever (on top right). German engineering and craftsmanship at its best.

improved and taken to the very boundaries of the technologically feasible by Peter Loseries and Otto Domes in terms of accuracy, reliability, whispering noise level on shooting the camera and shortest shutter lag between pressing the shutter release button and the exposure,

Peter Loseries in late eighties inside the Ernst Leitz Wetzlar factory in 1986, listening to the whispering sound of a Leica M6 mechanical shutter to check if it is working properly, something that he was able to tell by ear, thanks to his uncommon know-how and experience.

are by far the best made in the whole history of the analogue rangefinder cameras manufactured by the German photographic firm, culminating 50 years of evolution of Leica M shutters,

which are to a significant degree offspring of the shutter patent of March 10, 1934 presented by Ludwig Leitz.

The Leica M6 was basically a M4-P with a new TTL metering system, centre weighted, reading from a grey spot on the center of the cloth shutter.

Innards of the Leica M6 showing how Leica engineers and technicians managed to fill every millimeter of space inside the very small camera body with a number of mechanical, optical and electronic components. Such was the difficulty to find space, that the delay mechanism for the self-timer present in earlier Leica M models had to be done away with to make room for the two batteries and the electronics for the exposure metering circuit.

And that was a great success accomplished by the engineering team which took part in the creation of this rangefinder camera and were able to solve the huge challenge of fitting the TTL metering, all the electronic components, the battery and the mechanical shutter into the very small classic M body, making use of the scarce space available (much more limited than in an SLR camera) within the tiny construction, something really praiseworthy bearing in mind the technologies available at the time.

Needless to say that particularly the electronics had to be reduced in size further and further, until it was possible to incorporate it inside the camera´s body.

In this regard, it was also decisive the work fulfilled by Rolf Magel (Head of the Leitz Electronic Lab) and the prominent Leitz electronic designers Helmut Bill and Walter Bletz, who managed to downscale the dimensions of the electronic circuitry module (with surfaces on each side measuring 12,7 x 16,9 mm and containing six operations amplifiers, nine transistors, thirty-seven resistors and three condensers) for the Leica M6, as well as researching new technological approaches to get the best feasible position accuracy on bonding the chips of the circuit strip with the LED light balance in the viewfinder.

Year 1983. The first functional prototype of the Leica M6 has just been manufactured and a celebration for it is held inside the Ernst Leitz factory in Wetzlar. From left to right : Werner Schlapp (Head of the Photographic Lens Design Department), Wilhelm Buseck (Head of the Development Department), Peter Loseries (Engineer and Designer), Urs Scherrer (Chief Executive Officer), Willi Wiesner (Head of the Photographic Camera Design Department) and Werner Enke (Head of the Photographic Testing Department).

Therefore, the Leica M6 combined the classic craftsmanship and proven design of previous Leica M models with modern features such a bult-in TTL light meter, which significantly increased the camera´s appeal.

Bright round metering dot in the middle of the first curtain of the Leica M6. Sporting a diameter of 12 mm, the light coming in through the lens is reflected by the white measuring spot on the shutter curtain, captured and metered by a silicon photodiode placed at the top inside of the camera, behind the bayonet lens mount, making up a very accurate and reliable semi spot metering, which is turned on when tapping the shutter release button.

On the other hand, it was decided the Leica M6´s metering to be semi-spot center weighted, clearly indicating that the camera was intended to professional photographers, who had to be careful where they pointed the ragefinder patch on taking a meter reading.

Once the photographer presses slightly the camera´s shutter release button, the exposure metering starts operating, in such a way that the light balance in the rangefinder lights up and continuous measuring takes place, with the added advantage that the Leica M6 does its exposure metering selectively via the lens with working aperture, and once the shutter button is released, the exposure meter remains active during roughly 14 seconds.

This very special exposure metering implemented in the Leica M6 was greatly work of Peter Loseries and Otto Domes, who throughout some years before 1984 had already conducted experiments with focal plane shutters whose first cloth curtain had been provided with white patterns to reflect the light coming through the lens on a measuring cell in the front area of the camera´s body.

That reflection brought about a brightening of the space between the lens and the shutter curtain, and at the beginning of an exposure, this brightened space could generate a significant reduction of the image contrast, specially with good light conditions.

Therefore, both of them realized that only with the increased measuring sensitivity made feasible by the new electronics, was possible to do experiments with smaller white measuring sensitivity.

This way, the final choice for the Leica M6 was a round white measuring spot with a diameter of 12 mm, whose metal oxide colouring didn´t affect the flexibility of the shutter curtain rubberized cloth in hot or cold temperatures.

The Leica M6 introduction in 1984 marked a turning point in the history of Leica´s rangefinder cameras, definitely consolidating the presence of the M line of product in the photographic market and paving the way for subsequent analogue models like the Leica M6 TTL, Leica M7 and Leica MP.

Peter Loseries had a major role in the design and manufacture of the Leica M6, a symbol of photographic excellence and uncompromising craftsmanship, with which he reached his professional maturity alon with the Leica M6TTL introduced fourteen years later, in 1998.

But the biography of this genius of miniaturized engineering and mechanics was full of other amazing technical feats that confer him a pivotal role in the technological evolution of Leica between early seventies and late nineties.

Let´s see some of his main previous breakthroughs.

1971 : PETER LOSERIES AND PETER NOVAK DESIGN THE PRECISION MECHANISMS FOR THE SWIVELLING METER CELL OF THE LEICA M5

In 1971 Leitz launched into market the new Leica M5, first M rangefinder camera to offer TTL exposure metering and whose dimensions were larger than the previous Leica M models, because all the components of an exposure meter required a relatively big amount of space and could not be accommodated inside the already existing small RF camera bodies.

Therefore, Dietrich Brückner (engineer of the Leitz Electronic Development Department) devised a metering cell inside the camera body that would be placed in the path of the light crossing the lens (only if it was attached) when the shutter was wound, which would automatically swing out of the way on pressing the shutter release button and just before the exposure.

The accuracy mechanisms for this Leica M5 meter cell ( springing up when shutter was cocked, to read light through the lens, and retracting once more when you pressed the shutter or, for protection, when the lens was removed) were created by Peter Loseries and Peter Novak :

In spite of being a great photographic camera and by far the most advanced rangefinder model produced until then,

the larger body of the Leica M5 in comparison to the rest of Leica M cameras, its different contours with more angular shapes, its departure from the classic design of Leica M cameras and the new two-lug design ( which forced the camera to hang vertically, side-oriented, which felt awkward to many, unlike traditional horizontal hanging) made it a commercial failure, and only 33,900 units were sold during its four manufacturing years between 1971 and 1975.

Ernst Leitz Wetzlar had to stop manufacturing the M System cameras in Germany, and only the outstanding entrepreneurial talent and insight of Walter Klück (Director of Ernst Leitz Canada in Midland, Ontario) could save this lineage of 24 x 36 mm format rangefinder cameras, when he convinced Leica top brass to produce the new Leica M4-2 in Canada (1978-1980, with 16,000 units sold), which marked the return to the classic, compact M design complemented by advanced features such as motordrive compatibility.

Anyway, Leica had learnt that its future survival as a photographic firm depended on the creation of a new type of Leica slr camera, whose dimensions had to be very small, as well as featuring a light weight.

And to attain that compactness it was essential to manufacture a new kind of state-of-the-art electronic shutter boasting very little size, reduced weight and which could be produced at a low cost.

1976 : THE GROUNDBREAKING CLS METALLIC SHUTTER DESIGNED BY PETER LOSERIES MAKES A STELLAR APPEARANCE WITH THE LEICA R3

The twelve years elapsed between 1964 and 1976 saw the design, manufacture, evolution and end of a new breed of 24 x 36 mm format professional Leica single-reflex camera that would be consecutively embodied by the Leicaflex (1964-1968), Leicaflex SL (1968-1974) and Leicaflex SL2 (1974-1976).

This Leicaflex saga marked Leica´s entry into the 35 mm SLR market, trying to offer an exceedingly robust high quality alternative to the widespread Japanese single-reflex cameras from different brands.

They were superb cameras,

particularly the Leicaflex SL

and Leicaflex SL2, better built than true Japanese slr extraordinary flagships like the Nikon F, Nikon F2, Canon F1, Olympus OM-1, OM-2 and others, with the added bonus that they could be paired with the comprehensive range of Leica R lenses, by far the best in the world in the slr scope, in addition to featuring a state-of-the-art Rollo-Schlitzverschluss shutter ( a wonder of precision but rather expensive to produce and assemble) delivering a very soft diffused sound unlike any other camera in its product segment.

Suffice it to say that the Leicaflex SL2 was a stellar performer not only in terms of reliability, ruggedness, durability for many decades and advanced metering with its double photo resistor system, but also thanks to its exceptionally flat film plane and its incredibly smooth shutter mechanism (even by today´s standards).

But the production cost of the superb Leicaflex SL and SL2 was huge, since they were all-mechanical masterpieces of craftsmanship, manufactured with the best materials and noble metals in existence, were overengineered to a remarkable degree and required advanced technical abilities by highly experienced and knowledgeable workers for their production, so they couldn´t compete in price with the slr cameras made in Japan, a country where salaries were at the time much lower than in Germany.

And meanwhile, the Japanese photographic brands had been moving towards cost-optimized production and electronic camera technology, a field in which Leica had no experience.

It made that in spite of being the best slr cameras on earth at the moment, the Leicaflex SL and Leicaflex SL2 bodies were sold ( 70,000 and 24,555 units respectively, and 38,500 of the previous Leicaflex camera) at a loss, and only the price of the Leica R lenses generated some modest profit.

Leica had arrived late at the battle for world dominance of slr cameras, which was clearly won by the Japanese firms.

The situation had already become so critical for Leica since early seventies that its board of directors decided to make a last-ditch attempt to adapt to new times and restructure the company´s camera segment.

Right off the bat, it was apparent for them that the key aspects to improve were among others electronic technology, exposure metering, design of zoom lenses and cost-effective production.

This way, Leica decided to establish a technological partnership with Minolta, a Japanese firm with remarkable expertise in the field of electronics, circuit boards and exposure meterings applied to slr photographic cameras, as well as having proved its ability to create cost-effective products without lowering quality.

The goal was to generate a profitable cooperation between both companies, sharing know-how, patents, experience, state-of-the-art computer technology, different production methods and so forth.

And the first fruit of this alliance was the Leica CL, a compact M-mount rangefinder camera with a mechanical vertically running focal-plane shutter, through-the-lens Cds light metering and the Summicron-C 40 mm f/2 and Elmar-C 90 mm f/4 as main primes (the camera was marketed in Japan as Leitz Minolta CL with Rokkor lenses).

Peter Loseries created some parts of this camera, designed by Karl Clös and manufactured in Japan.

Produced between 1973 and 1976, it was an endeavour to create a less expensive entry into the Leica M world, becoming a successful camera that reached the figure of 65,000 units sold.

Anyway, Leica knew that the key factor for the success of its partnership with Minolta would be the design and manufacture of a new breed of professional single-lens reflex camera replacing the extraordinary Leicaflex SL and Leicaflex SL2, which hadn´t been commercially viable because of the aforementioned market circumstances and Leitz´s delay in joining to the predominant slr trend.

After the agreement between Leica and Minolta was signed in Osaka (Japan) between Knut Kühn Leitz (Managing Director of Leitz, sent by Ernst Leitz III and Ludwig Leitz) and Kazuo Tashima (President of Minolta) in april of 1971, it was thought that the Japanese company would have the upper hand, because it was a much larger corporation with far superior economical means and wherewithal of its own to invest on R & D, as well as being very ahead of Leica in electronics and design of zooms.

But there was a pivotal and absolutely fundamental component necessary for the creation of such a new generation of small slr camera and guaranteeing its flawless operation and market success : the shutter.

Both Leica and Minolta thought that it was indispensable to provide the new professional slr camera with a small size, top-notch and exceedingly dependable electronic vertically travelling focal-plane metal blade shutter, because it has only 24 mm to cover, while a Leica-type cloth shutter running horizontally needs to cover 36 mm.

Besides, the overall mass of all the moving parts in a shutter essentially made of ultra-thin spring-loaded blades is much lower than that of long horizontally-traveling rubberized curtains mounted on revolving drums.

Therefore, the lower inertia that this vertically-traveling shutter mechanism needs to overcome in symbiosis with its metal build and its shorter travel distance make for a shutter that is much sturdier and durable, can be controlled with more precision, and needs less maintenance.

That´s why both Leica and Minolta knew that they needed a new and very small electronic plane-focal vertically-running shutter different from the excellent Barnack type Rollo-Schlitzverschluss horizontally travelling focal-plane shutter with cloth curtains (very reliable, with varying slit changing its width according to the exposure time, but with which it was very difficult to achieve shorter exposure times than 1/1000 s and whose flash synchronization speed was limited to 1/60 s).

It had also to be different from the Japanese mechanical focal-plane vertically travelling Copal Square I metal blade shutter from 1960 (which had been delivered to some camera manufacturers as a very convenient drop-in module), the Copal Square S (one of the most reliable mechanical shutters ever made) and the electronically controlled and also focal-plane vertically travelling Copal Square E from 1968, both of which were very big and needed a certain height of the camera.

This way, Knut Kühn Leitz and Kazuo Tashima kept on between 1971 and 1973 elaborating on the inception of a new type of professional slr camera built by both firms to consolidate their market future, until suddenly, Ernst Leitz III´s nephew unveiled the ace up its sleeve held by Leica : the extraordinary and revolutionary electronically governed and vertically running metal focal-plane Copal Leitz Shutter (CLS), designed by the genius Peter Loseries in 1973, sporting very little size, exceedingly low weight and a reduced number of blades.

Kazuo Tashima was very impressed by Peter Loseries´ groundbreaking design, so Minolta and Ernst Leitz Wetzlar decided that the Japanese firm Copal manufactured it, to reduce the series production cost of the new slr camera.

Electronic controller side of the CLS electronic shutter created by Peter Loseries.

This mastepiece shutter was a marvel of mechanics and electronics engineering miniaturization,

Film side of the CLS electronic shutter designed by Peter Loseries. With its arched guides, it guarantees the movement of blades in a minimum space.

being 7 mm shorter, 4 mm narrower and weighing 15 percent less than the Copal Square Shutters, as well as having fewer blades and a simplified construction which significantly eased mass production with low cost without compromising the quality and long duration of the device.

In addition, Peter Loseries attained a further amazing achievement with his CLS shutter : it worked very quietly and vibration-free.

As a sign of friendship, Leica let that this groundbreaking electronic CLS shutter was first incorporated in the Minolta XE-7 slr camera launched into market in 1974.

And the Leica R3, first camera of the second lineage of slr models manufactured by Ernst Leitz Wetzlar, was launched into market in 1976, also incorporating the vertically travelling metal blade focal-plane electronic Copal Leitz Shutter (CLS) created by Peter Loseries, in addition to featuring the innovative dual metering system, offering both spot metering and integrated centre-weighted metering (selected via a small lever below the shutter speed dial).

The R3 was built on the same platform as the Minolta XE-7 and shared many parts with it, though the Leitz model offered key upgrades : a brighter viewfinder, a dual-mode meter with center-weighted and spot metering (whereas the XE-7 lacked spot metering), later support for a motordrive and Leica R mount for the best reflex lenses in the world (the XE-7 used SR mount for excellent Rokkor lenses and an overall more favourable price).

70,000 units of the Leica R3 (first Leica slr camera with automatic exposure) were sold between 1976 and 1978, years in which it was manufactured.

A very good figure (the same as the Leicaflex SL2, but with a much lower production cost) for a small company like Leica, which enabled it to succesfully start its new breed of slr professional models, making it profitable.

1980-1987 : THE MFC-ES ELECTRONIC SHUTTER MANUFACTURED BY SEIKO, GREATLY BASED ON PETER LOSERIES´ VERTICALLY RUNNING METAL BLADE CLS SHUTTER AND BUILT IN AN EVEN SMALLER SIZE REACHES A GREAT SUCCESS WITH THE VERY LITTLE LEICA R4

The slr Leica R4 camera, designed by Heinrich Janke and Hans-Kurt Uellenberg, was introduced in 1980 and meant a significant improvement in terms of compactness and light weight, to such an extent that after thoroughly testing the Leica R4 MOT Electronic,

Norman Goldberg (a world-class pundit on mechanics of photographic cameras and an outstanding instrument maker) wrote an insightful review in Popular Photography magazine, praising the following virtues of this second model of the Leica R saga in comparison to the previous Leica R3 :

- It is noticeably smaller (138.5 x 88 x 60mm) and lighter (680 g) than the Leica R3 (148 × 96.5 × 64.4mm and 780 g).

- It boasts a highly sophisticated metering system with five metering modes ( program automatic, aperture priority with spot metering, aperture priority with center-weighted metering, shutter priority with center-weighted metering and full manual control), all selected by the use of a single dial on the camera top plate.

- Five different available interchangeable finder screens.

- Motorized operation with either a 2fps or 4fps drive unit.

Electronic controller side of the MFC-ES electronic shutter created by Seiko and clearly based on the likewise electronic CLS shutter designed by Peter Loseries, reaching its evolutive pinnacle, with a height of only 51 mm and 31 g less.

- The Seiko MFC-ES electronic vertically running metallic shutter with speeds between 1 and 1/1000 s + B,

Film side of the MFC-ES electronic shutter created by Seiko. Its visible arched guides, guaranteeing the movement of blades in a minimum space prove beyond doubt that this extraordinary device was greatly based on the also electronic CLS shutter designed by Peter Loseries and manufactured by Copal, which meant a quantum leap in the history of vertically running and metallic electronic shutters.

working on the principles of the landmark CLS electronic vertically travelling metal blade focal- plane shutter shutter created by Peter Loseries, but now manufactured by Seiko instead of Copal, to reduce the production cost, since it was also independent from the rest of the camera and easily assembled.

- The state-of-the-art system devised by Leitz to allow both spot and average metering, with the main reflex mirror passing 30 percent of the light through its 17 layer coating to a secondary mirror hinged to the rear of the main mirror´s panel, whereas the secondary mirror is about as large as the main mirror and swings down to a position just in front of the shutter blades during the viewing phase of operation.

The light metering system used on the Leica R4 is a design wonder. Here can be seen the camera in upwards position, showing its very sophisticated and semitransparent Fresnel mirror (visible in the image) coated with 17 different layers to produce precisely the reflection transmission characteristics which Leica wants. Light coming through the lens strikes that amazing mirror, and thirty percent of the light passes through it, inciding on a complex mirrored reflector made up of 1345 tiny reflectors which concentrate the light and precisely reflect it down to a single photo cell in the base of the camera´s mirror box.

And above all, Norman Goldberg extolled the most fascinating trait of the Leica R4 : its myriad of 1,345 tiny concave reflecting lenslets placed on the surface of a plastic panel, arranged in such a way that produce an off-axis Fresnel mirror, whose effective focal length and angle make that the exit pupil of the camera´s lens be brought to focus on the single silicon cell situated on the floor of the mirror box, up towards the camera´s front.

Therefore, he explained how this metering system provided spot and average readings using a single photocell at the front edge of the mirror chamber´s floor, in such a way that to switch from full area to spot metering, Leica designed for this camera a concentrating lens which is mechanically moved in front of the meter cell and restricts the light striking the cell to just 7 mm in the very center of the image, which is also delineated by a circle marked on the focusing screen.

The Leica R4 was a great success, with 125,000 units sold during its seven years of production, and its rock-solid reliable Seiko MFC-ES (MFC stands for Metal Focal Plane Compact and ES means Electronic Shutter) electronic shutter enhanced even more the prestige of Peter Loseries, since it was clearly inspired by its milestone and pioneering CLS shutter, and subsequently equipped a lot of 24 x 36 mm format professional reflex photographic cameras from a number of different Japanese brands, including Nikon and Pentax.

On the other hand, the level of miniaturization and light weight of the Leica R4 was so stunning (138.5 x 88 x 60mm and 680 g) that it reduced distances in dimensions and weight with the unbeatable in this scope all mechanical Olympus OM-1 from 1972 (136 x 83 x 50 and 490 g and made between 1972 and 1988) and the aperture priority automatic exposure with electronic shutter Olympus OM-2 from 1975 (featuring exactly the same dimensions as the Olympus OM-1, with a weight of 520 g and manufactured between 1975 and 1988), designed by the genius Yoshihisa Maitani, an engineer whose aim had always been to build a 24 x 36 mm format slr camera featuring the size of a screwmount Leica.

But both the mechanical horizontally travelling cloth focal-plane shutter of the Olympus OM-1 and the electronic horizontally travelling cloth focal-plane shutter of the Olympus OM-2 had a relatively slow flash synchronization speed of 1/60 s, along with TTL off-the-film metering, compared to the more efficient electronic vertically running metal blade focal-plane Seiko MFC-ES shutter of the Leica R4, which had a much more complete TTL metering system and a flash synchronization speed of 1/100 s, as well as boasting a reference-class spot meter not influenced at all by stray light.

Innards of the Seiko MFC-ES electronic shutter of the Leica R4, designed and manufactured greatly following the working principles and abundant innovation of the landmark CLS electronic shutter created by Peter Loseries and manufactured by Copal for the Minolta XE (1974) and Leica R3 (1976).

Needless to say that this extraordinary Seiko MFC-ES electronic shutter of the Leica R4, mostly descendant of the breakthrough also CLS electronic shutter designed by Peter Loseries for the Leica R3, made a great difference, since it improved the brainchild of the eminent German engineer and designer, with a three stage device :

a) The first one switching on metering and LED display for exposure.

b) The second one in aperture priority, locking the exposure value by holding pressure (making the red " A " dot disappear).

c) The third one with the final press, firing the shutter after the camera performs a quick exposure double-check for accuracy, guaranteeing a correct light measurement even with older lenses.

GREAT FRIENDSHIP WITH NORMAN GOLDBERG

Peter Loseries had a great friendship with another genius :

Norman Goldberg photographed by Peter Loseries inside the Ernst Leitz Wetzlar Museum in 1980. He is holding in his hand the mythical prototype Ur-Leica, designed by Oskar Barnack in in 1914, first 24 x 36 mm format camera in history and the most influential one.

Courtesy of his son Don Goldberg. DAG Camera Repair.

Norman Goldberg, one of the most important and knowledgeable experts testing photographic cameras and lenses ever.

He was technical consultant of Popular Photography magazine from 1966 and one of the main architects of its international success, thanks among many other things to the extraordinary lens testing program he devised, creating his unique MTF test laboratory, joining the staff of the magazine in 1972, and being its technical director until his retirement in 1987.

Born in 1931 in Chicago (Illinois), after a five year apprenticeship and attending the Illinois Institute of Technology, he moved to Wisconsin in 1951, where he established Camcraft, an independent workshop which specialized in repairs and custom modifications to professional photographic equipment.

In addition, he was trained at Leitz New York in mid fifties and founded the first authorized Leica Repair Shop outside Leitz New York, with great success.

He tested some of the first MTF optical benches and was a remarkable innovator with a number of technical solutions for all kind of photographic tools, particularly for Leica M cameras, accomplishing a lot of technical feats, among which must be underscored :

Camcraft N-5 designed by Norman Goldberg coupled to a Leica M2 with Elmar 50 mm f/2.8 and early silver chrome Leicavit MP rapid winder.

- The creation in 1962 of the Camcraft N-5 electric motor drive for the Leica M2 and MP rangefinder cameras, made up by the Leicavit-MP and a grip containing the motor, a better, sturdier and more efficient device than the very good experimental units of motorized Leica M3 cameras built by Leitz designer Werner Hilgendorf in 1957 and the benchmark in this regard along with the motorized drives created by designer George Mann (greatest expert in motors for photographic cameras at Leitz) for Leica single-lens reflex cameras during seventies and the Leica Winder M introduced in 1987 and designed by him and Günther Brück, which was an evolution of the Leica Winder M4-P created by the latter.

Such was Norman Goldberg´s skill, passion and ingenuity as a photographic instrument maker and designer of miniaturized mechanics optimized for 24 x 36 mm format cameras, that Bob Schwalberg, Leitz New York liaison for American photojournalist, who had an office at Leitz Wetzlar and friendship with Alfred Eisenstaedt, had encouraged Norman Goldberg since early sixties to design this amazing Camcraft N-5 electric motor drive, which used state-of-the-art and highly reliable microswitches used by the NASA and only available at the time in United States.

- A number of modifications of the Visoflex, using either a prism or a pellicle mirror.

- The design and manufacture of a lot of testing equipment to analyze cameras and lenses, including the one used at Popular Photography, who was for more than two decades the reference-class on earth.

- The praiseworthy conversion to M mount of six Leica IIIg originally screwmount cameras, inspired by the Prototype Leica IIIg in M mount he had been shown during a visit he made to Wetzlar in late fifties.

From left to right : Norman Goldberg, Walter Klück and Ernst Leitz III in Wetzlar (Germany) in late seventies, photographed by Peter Loseries. The genius founder of Camcraft appears with a Leica M4 (his favourite camera) coupled to a chrome plated brass and retractable 7 elements in 6 groups Summicron-M 5 cm f/2 First Version (1953-1960) with 12538 shade. Ernst Leitz III had Norman Goldberg in great esteem and gave him a drawing made by himself of the first Leica body shell manufactured with aluminum tubing, aside from buying some of his patents.

Courtesy of his son Don Goldberg. DAG Camera Repair.

On the other hand, he had friendship with Ernst Leitz III and Walter Klück ( President of Ernst Leitz Canada ), being a passionate user of Leica M cameras and a good photographer.

He was one of the foremost testers of professional analogue photographic cameras and lenses of all time, and probably the number one in terms of technical knowledge and expertise in that field, having made a lot of landmark articles

like the one on the Leica M4 published in the Popular Photography magazine number of March 1968, painstakingly made with the optical chart invented by him and a special 100x microscope, with the chart having high and low contrast targets as well as other devices for checking possible lens aberrations, the optical bench equipment being mounted on a very heavy table for exceptional stability and stopping down lens as chart was examined, checking points at which such aberrations as coma lessened or disappeared.

Moreover, he was author of Camera Technology, a reference-class lavishly illustrated book in which he displays his impressive knowledge on mechanics and physics in synergy with uncommon practical skills, ingenuity and proficiency in all kind of intricate technical aspects, having also been a friend of Erhard Glatzel and Hans Sauer, two eminent Zeiss Oberkochen optical designers.

THE AMAZING MECHANICAL LEICA STROBOSCOPE SHUTTER TESTER AS KEY DEVICE TO IMPROVE THE OPERATING ACCURACY OF LEICA M AND R CAMERAS

Ernst Leitz GmbH Wetzlar analog stroboscope shutter tester made in mid seventies.

Throughout seventies, eighties and nineties of XX Century, Leica technicians, engineers and designers used very frequently a stunning analog stroboscope shutter tester for Leica M and R cameras.

Peter Loseries and Otto Domes took advantage of its amazing performance during their intensive research to improve the mechanical shutter of the Leica M4-P (1981-1987) and provide the Leica M6 from 1984 with a better one, something for which it was necessary to precisely measure the fastest speeds of the cameras (1/250, 1/500 and 1/1000), because mechanical shutters aren´t as accurate as the electronic ones, in addition to also visually check shutter bounce, travel times and tapering.

And they managed to measure a millisecond mechanically, with this unique machine that creates a rolling shutter effect that you can see with your eyes, thanks to the persistence of vision, approaching the camera to its image port and shooting it at different shutter speeds,

Operating and calibration instructions of the mechanical Leitz Stroboscope Shutter Tester from mid seventies, highlighting the importance of the aperture showing a neon lamp placed on the left hand side of the green window and used to calibrate the machine, and also the different patterns of slightly bent diagonal lines that could appear inside the image port and indicate too slow shuter speed, too fast shutter speed, correct shutter speed and shutter bounce.

checking their accuracy by means of the observation of different patterns with shape of a bit curved diagonal lines appearing through the camera´s shutter during the exposure time and depending on how those patterns line up with the reference images in the service manual for that particular camera, you could tell whether a given shutter speed was firing too fast or too slow.

If the bands of light are parallel and even across the frame, the shutter is running correctly.

If they are significantly wider at the base of the slit, then the second shutter curtain is too slow.

If the slits are narrower or non existent at the base, then the second shutter curtain is too fast or the first is too slow.

This mechanical Leica stroboscope shutter tester is started with an octogonal black colour switch, positioned on the right side of the machine and turning on the appliance, coupled to the 220 v 50 Hz electrical network.

From that moment on, you have to look through the image port (it is the observation rectangle on top front area of the machine), checking the diagonal lines appearing inside it on approaching the camera towards the stroboscope shutter tester and shooting it with its shutter open, adjusting the device until the speeds are within tolerances.

On the other hand, the angle and shape of the bands gives information on the travel time, while the curvature and number of slits indicate correct or incorrect shutter travel.

GREAT EVOLUTION IN THE DESIGN OF TESTING INSTRUMENTS FOR FLASH SYNCHRONIZATION AND TTL FLASH METERING

Leitz analogue testing instrument from early sixties to check the flash synchronization of Leica M3 and M2 cameras.

The progressive evolution of Leica in flash implementation on its cameras, from the screwmount Leica IIIF (1950-1957, first Leica rangefinder camera with built-in flash sync, at a speed of 1/50 s) to the Leica M6 TTL (1998-2002) boasting flash TTL metering, prompted that increasingly better machines were built for both checking the flash sync precision ( all of Leica M cameras having a common sync of 1/50 s, while the Leicaflex SL and Leicaflex SL2 feature a flash sync of 1/100 s, the Leica R3 1/90 s, the Leica R4 1/100 s, the R5 1/1000 s, the R6 1/100 s, the R6.2 1/250 s or higher with High Speed Sync and the R7 1/100 s)

and the accuracy of the TTL flash metering trailblazed by the Leica M6 TTL (1998-2002), in which Peter Loseries managed to improve the mechanical focal plane shutter even more with respect to the original M6, in cooperation with Otto Domes (technical project director of the 1998 camera, having already created in July of 1984 the circuit diagram for the TTL metering of the Leica M6), who excelled with its new TTL flash metering and the two circuit boards making it function, along with the larger shutter speed dial, and a top plate 2 millimeters higher than in the Leica M6, to accomodate the additional electronics, having risen up to the major challenge of installing the highly miniaturized electronics within the very small camera body with rather scarce available space.

LEICA M6 ELECTRONIC FROM 1979-1981 : THE GROUNDBREAKING PROJECT BY PETER LOSERIES THAT DIDN´T REACH COMMERCIAL PRODUCTION

The introduction of the Leica M6 in 1984 definitely saved the Leica M rangefinder lineage and paved the way for a strong renaissance of the analogue RF segment of cameras between 1999 and 2009, both Leica ones and from other brands in M mount, embodied by the Konica Hexar RF (1999), Bessa R (2000), Bessa R2 (2002), Rollei RF (2002), Leica M7 (2002), Leica MP (2003), Bessa R2A and R3A (2004), Zeiss Ikon ZM (2004), Bessa R2M and R3M (2006) and Bessa R4A and Bessa R4M (2009, amazing designs with 0.52x VF optimized for 21/25/28 and 35 mm wideangle lenses, as well as enabling to easily use 50 mm lenses).

But things could have been other way.

In late seventies, Leitz designers had the integration of TTL metering into a Leica M camera as a major technical challenge and top priority, so Peter Loseries had the idea of using the Leica R4 with Seiko MFC-ES shutter (based on its CLS shutter, but smaller and lighter) as a platform, taking off the mirror box, pentaprism, top cover, focusing screen, preview lever, spring loaded diaphragm mechanism and R bayonet (replaced by an M one), installing a rangefinder and reconfiguring parts of the exposure meter and the electronics.

The four prototypes built with these premises were called Leica M Electronic, featuring a totally new TTL exposure metering system created by Peter Loseries and Otto Domes, optional automatic exposure and a large camera rear door opening horizontally, with the added benefit of compatibility with the R4 winder, drive and databack.

It meant an utterly new design, departing from the classical Leica M concept, and one of its most important goals was to significantly drop the production cost while preserving the optomechanical quality.

This Leica M electronic created by Peter Loseries was so stunningly avant-garde that it was provided with an automatic aperture priority mode, something that wouldn´t appear in any Leica M camera until the introduction of the Leica M7 in 2002, twenty-three years later.

The idea was to upgrade the Leica M with an electronic shutter as camera core, but from scratch, it became an exceedingly difficult technical tour de force to tackle and a bit risky to implement, because of two main reasons :

a) The shutter parts taken from the R4 worked flawlessly in an slr camera, but needed some changes to install them inside a mirrorless rangefinder body, which resulted in light leak problems which were very difficult to resolve.

b) The internal room of a Leica M camera is very limited to introduce additional circuitry, so the electronics needed for automatic exposure had to be designed with new layouts and more stringent manufacturing tolerances.

Besides, Leica´s customers were highly conservative regarding the more rounded shape of Leica M bodies and preferred their mechanical shutter, which enabled more decades of intensive use of the camera and were simpler and less expensive to fix, being straightforwardly serviced by skilled technicians.

Front view of one of the Leica M6 Electronic prototypes, showing the Fresnel reflector beyond the M mount, and on top of the camera the fairly miniaturized electronic circuitry and microchips handling the Seiko MFC-ES electronic shutter, the TTL metering and the automatic aperture priority exposure.

The Leica M6 Electronic was a fascinating technological project that perhaps could have given rise to the creation of a new breed of Leica M camera from early eighties, with a significant reduction in manufacturing cost, on sharing a host of components and production stages with the Leica R4, while keeping quality and also using the superb Leica M lenses, as well as harnessing the invaluable bonus of a new electronics for the selective and integrating exposure metering, for the control of the metal blade vertically running focal plane shutter and for the displays in the viewfinder, aspects which were developed by Rolf Magel (Leica Manager of the Electronics Development Department).

Moreover, Erich Mandler managed to get the adequate adaptation of the range-viewfinder and the display of the LED exposure meter readings in the VF of the Leica M6 Electronic prototypes, while Otto Domes and his team including André de Winter, Peter Hötte, and Reinhardt Wachter made the necessary mechanical changes in the film advance and shutter winding, in addition to designing the intricate mechanism for the Fresnel reflector that was shaped like a concave mirror that had to be swung into the light path of the lens for both the selective and integral meterings to deflect the light toward the silicon photodiode placed in the lower area of the camera.

But solving the problem of light leak kept on being an unsurmountable challenge,

Cutaway of the Leica R4 with a 6 elements in 4 groups Summicron-R 50 mm f/2 Version 2 (1976-2009). In the middle of the image can be seen the Fresnel reflector in the mirror, the profusion of electronic circuitry behind the letters LEICA governing the different automatic exposure modes, and under the shutter speed mode are the electronics controlling the Seiko MFC-ES shutter.

because in a reflex camera like the Leica R4, though the fabulous Seiko MFC-ES electronic shutter wasn´t completely light-tight, it didn´t mean a major concern and worked like a charm, since the hinged mirror in front of that shutter deflected very bright light away from it, whereas the Leica M Electronic prototypes were rangefinder cameras and hadn´t any mirror whatsoever.

Peter Loseries expressed his conviction that he would be able to solve this key aspect (and evidence suggests that he would have attained it), but in 1981 (year in which the Leica M6 electronic prototypes were finished) Leica was still immersed in a fight for survival after the saving of the M lineage of rangefinder cameras by Walter Klück only four years before, in 1977, when the production of the Leica M4-2 was transferred to the factory of Ernst Leitz Midland Ontario (Canada), so the German photographic firm, whose economical benefits had significantly dwindled in comparison to fifties and sixties, decided to bet on the design and manufacture of the much more classic and mechanical Leica M6, launched into market in 1984, featuring TTL metering and which was an outstanding sales success : 175,000 units of the Leica M6 between 1984 and 1998 and 50,000 units of the Leica M6 TTL between 1998 and 2002.

Whatever it may be, the Leica M6 Electronic prototypes designed and built between 1979-1981 proved once more Peter Loseries´ tremendous knowledge, experience and creativity, giving birth to these amazing rangefinder hybrid cameras (a kind of mixture of traits from the Leica M4-P and Leica R4 electronic, while body contours and top plate were more leaning towards the Leica M5), technologically twenty-three years ahead of their time and which turned into the groundwork for the future design and manufacture in 2002 of the electronic Leica M7, also featuring automatic aperture priority.

A FAR-REACHING INFLUENCE IN THE PHOTOGRAPHIC WORLD BOTH IN XX AND XXI CENTURIES

Peter Loseries was one of the most important design engineers ever in the scope of photographic cameras, along with Oskar Barnack, Yoshihisa Maitani, Ludwig Leitz, Hubert Nerwin, Karl Nüchterlein, Tetsuro Goto, Willi Stein, Norman Goldberg, Georg Mann, Kunio Simoyama, Otto Domes, André de Winter, Manfred Meinzer, etc.

Gifted with an extraordinary mechanical insight, electronic know-how to spare and staggering ability to deal with the most complex technical challenges, his labour as engineer and designer was highly influential not only within Leica, but however incredible it may seem, also in the whole Japanese photographic industry from mid seventies until nowadays, well advanced the XXI century.

He was a visionary man in a raft of technical concepts, and as a matter of fact, his landmark CLS electronic shutter made by Copal from 1974, was a true masterpiece in terms of compact dimensions, low weight and exceedingly reliable performance, enabling the creation of smaller body cameras with plenty of electronics inside, automatic exposure and different metering modes.

The Japanese realized that Peter Loseries (who had a great friendship since 1971 with Toshio Tayashi, a Minolta designer expert in the field of electrically controlled self-timer devices for single-lens reflex cameras) was a wizard in the creation of miniaturized shutters for photographic cameras and that the electronic metal blade and vertically running CLS shutter designed by him was undoubtedly a game changer.

Therefore, a comprehensive team of experts from the Japanese firm Seiko studied thoroughly the CLS shutter during two years, and in 1976 it introduced the even more extraordinary, smaller and lighter MFC-ES electronic shutter (featuring five opening and six closing blades), greatly based on the principles pioneered by Peter Loseries in his CLS device, which would also be incorporated in the Leica R4 when it was launched into market in 1980.

This Seiko MFC-ES electronic shutter was used by many popular 24 x 36 mm format slr Japanese cameras from different brands, like the Pentax ME (1976), Minolta XD-7 (1977), Nikon EM (1979) and Pentax MV (1979), while the Pentax EM Super (1979), Chinon CE-5 (1981) and the Pentax Program A (1984) used the improved version Seiko MFC-ES2 shutter.

But neither the Seiko MFC-ES nor the Seiko MFC-E2 would have been possible without Peter Loseries´ CLS shutter, which was their forebear to all intents and purposes, so he had a deep influence

in the diminutive dimensions and weight of Japanese cameras like the Pentax EM Super (131,5 x 83 x 49,5 mm and 460 g) incorporating the Seiko electronic shutter clearly based on the milestone one previously created by the Leitz German engineer and designer.

On the other hand, with stunning anticipation, his commendable labour with the four Leica M6 Electronic prototypes made between 1979 and 1981 set the foundation for the design and manufacture of the Leica M7 in 2002, a great technological feat accomplished by Otto Domes (Manager of the Leica M7 Development Project) and Rolf Magel, who could solve the challenge of getting a top-notch electronic shutter and a very complete automatic exposure time control with aperture priority inside the tiny camera body (something much easier in slr cameras sporting larger dimensions), as well as having built into the camera more than 350 newly designed or modified components and having attained two further remarkable achievements : a shutter lag of 12 ms, far shorter than the cream of the crop of slr cameras, and a special high speed synchronization (HSS) function making possible flash sync speeds of up to 1/1000 s.

Also amazingly, some of Peter Loseries´ miniaturization technical keynotes applied to the innards of analogue photographic cameras, including to leverage underutilized space within camera bodies, have progressively been implemented during XXI Century in a number of very small EVF full frame also mirrorless digital cameras from different brands boasting very small dimensions and light weight.

And last but not least, Peter Loseries envisaged the seminal importance of the Leica M6 (first classic Leica M body in which was possible to integrate through-the-lens exposure metering, highly encouraged by Dr. Werner Simon, Leica Head of Production and Photo Division at the time) for the consolidation of the Leica M concept in late XX and XXI Century, with a flawless analogue /digital transition, epitomized by the full frame Leica M9 digital rangefinder camera in 2009 and all the subsequent Leica M digital models appeared hitherto.

And the recent launching into market in october of 2022 of the new Leica M6 has utterly confirmed the revival of film photography, as well as speaking volumes about the present full validity of the tenets established with the original camera from 1984 by the likes of Peter Loseries, Otto Domes, Rolf Magel, Helmut Bill, Walter Bletz, Doris Schmitt, André de Winter, Manfred Weimer and others :

Leica M6 from 1984 giant display model exhibited during the Leica Centenary Exhibition inside the Fernando Fernán Gómez Cultural Center in Madrid (Spain) between september 10, 2025 and January 11, 2026 and organized by Leica Camera AG.

This legendary 24 x 36 mm format rangefinder camera was the first classic M model to offer TTL metering and three versions with different viewfinder magnifications : 0.58 x, 0.72x and 0.85x.

Forty-one years after its launching into market, this camera goes on enthralling every person beholding it, thanks to its timeless beauty, elegance and minimalist design with exceedingly attractive rounded contours and only the essential elements and dials necessary for a complete control by the photographer, fostering his/her creativity. In addition, its utterly mechanical focal-plane horizontally travelling shutter with rubberized cloth curtains is the evolutive pinnacle regarding reliability, precision and duration in time, since it was created by Peter Loseries and Otto Domes improving the already excellent and also mechanical shutter operating with the same principles (designed by Willi Stein and Ludwig Leitz) featured by the previous Leica M cameras from 1954, greatly safeguarding at the same time the dynamic principle of the independent travel of the shutter curtains that had been mathematically researched by Professor Riede during fifties, as part of the strenuous efforts to improve the travel cycle of the mechanical Leica M focal plane shutter that had been constant from that time.

Another image of the giant display of the Leica M6 from 1984 during the Leica Centenary Exhibition inside the Fernando Fernán Gómez Cultural Center in Madrid (Spain) in 2025, organized by Leica Camera AG, now showing its back area with the viewfinder on the upper far left of camera rear, which unlike the VF of a slr camera (placed in the middle of its backside and only seeing what the lens sees), enables that the photographer can see with his/her right eye in the viewfinder what the camera sees, while his/her left eye keeps on seeing everything happening outside the frame, in such a way that you are seeing the unfolding photographic instant and the context, so the chances of creating a good image composition, selecting what you put inside the frame and what you leave out, are significantly enhanced.

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Tuesday, January 13, 2026

PETER LOSERIES : A HISTORICAL WORLD-CLASS EXPERT IN LEICA CAMERAS SHUTTERS AND KEY FIGURE IN THE CREATION OF THE LEICA M6

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