50MM SCREW MOUNT LENSES

It is important to note that Leica lenses had their focal lengths specified in millimeters from 1925 to 1928, in centimeters from 1928 to 1970, and again in millimeters from 1971 onwards³⁶⁰.

50mm f/3.5 Leitz Anastigmat

Max Berek developed a five-element lens, with the three rear elements cemented together, for the "Null-Serie" cameras (starting with the one that has the serial number 105³³⁷) and early Leica I Model A cameras²⁶⁰ from serial number of 126 to approximately 300³⁶⁰. Although specifically designed by Berek, the lens was based on the earlier Anastigmat and was initially named as such due to various pending patents. It had a focal length of 50mm, with apertures ranging from f/3.5 to f/12.5³⁶⁰. One of its innovative mechanical features was the ability to collapse the lens tube into the camera, allowing for a very compact design³⁶⁰. In this stowed position, the lens barely protruded from the camera body³⁶⁰.

Anastigmat lenses were black for the “Null Serie” cameras and nickel for Leica I Model A³⁶⁰. Three fine lines are visible on the draw tube of this collapsible lens³⁶⁰. These lines must align with three corresponding marks on the focusing mount for the lens to be collapsed³⁶⁰. This 'line' alignment technique was discontinued for some time but reappeared with the 5cm f/2 Summar Collapsible lens in 1933³⁶⁰.

50mm f/3.5 Leitz Elmax

After the patents expired, the name of the lens was changed from Anastigmat to Elmax, a name derived from the initials of E. Leitz and Max Berek³⁶⁰. Approximately twelve hundred Elmax lenses were fitted to Leica I Model A²⁶⁰ cameras with serial numbers ranging from 300 to 1500³⁶⁰. Similar in design to Anastigmat³⁶⁰, this lens had five-element, three group lenses with the last group composed of three cemented elements²⁶⁰.

50mm (5cm) f/3.5 Elmar

The Elmax lens was eventually recomputed, and thanks to new glass technology, Berek was able to reduce the number of elements in the rear portion of the lens from three to two³⁶⁰. This redesign resulted in a lens consisting of only four elements, with the two rear elements cemented together³⁶⁰. The lens was then renamed Elmar in 1926²⁶⁰, a name that was more pleasing than Elmax³⁶⁰. The decrease in the number of glass elements led to significant savings in production costs, both for the lens itself and for the Leica I cameras that it accompanied³⁶⁰.

From its early days, the 50mm f3.5 Elmar lens achieved worldwide success. It was the only lens supplied with the Leica I, aside from a few hundred 50mm f2.5 Hektors produced several years later³⁶⁰.

The design of the 50mm Elmar (later versions were engraved with "5cm") remained fundamentally unchanged from 1925 until 1962, although it was offered in numerous variants³⁶⁰. Before discussing these variants, it is important to define the terms 'coupled' and 'standardized' in this context³⁶⁰. A coupled lens is one that aligns with a built-in rangefinder, making it usable with that feature³⁶⁰. A standardized lens, on the other hand, aligns with the body of any Leica model, though not all standardized lenses are coupled³⁶⁰.

The early lenses for the interchangeable Leica I model were neither coupled nor standardized; each lens had to be individually matched to a specific body³⁶⁰. To ensure correct pairing, the lenses were engraved with the serial number of the corresponding body³⁶⁰. Initially, the complete five-digit serial number was engraved, but later it was simplified to the last three digits³⁶⁰. The standardized lens was introduced later, marked with an "O" engraved on both the lens mount and its mounting flange³⁶⁰. With the release of the Leica II, which included a built-in rangefinder, all lenses had to be fitted with a coupling ring; otherwise, the rangefinder could not be operated³⁶⁰. From 1932 to 1939, Leitz offered a service to convert uncoupled and/or unstandardized lenses into coupled, standardized ones³⁶⁰.

Early Leitz lenses, whether normal, wide-angle, or telephoto, were available in the following forms³⁶⁰:

(1) individually matched and marked with a three- or five-digit "compatibility" number³⁶⁰;

(2) with a standardized mount³⁶⁰; or

(3) standardized and coupled³⁶⁰

Most Leitz lenses focus to 3 feet (1 meter), with a few noted exceptions³⁶⁰.

The 50mm (5cm) f/3.5 Elmar lens was a variation of the well-known "Triplet" design, which took full advantage of its excellent correction capabilities. This allowed for the minimization of both chromatic and monochromatic residual aberrations. The lens was exceptionally sharp at its maximum aperture and reached peak performance at a diaphragm setting of f/8. It offered a total field of view of 48°, with a vertical angle of 27° and a horizontal angle of 40°³⁵⁸.

Variants

Variant 1 is a nickel 50mm Elmar in a non-interchangeable mount fixed to Leica I Model A; from approximately camera serial number 47000, the lens includes a depth-of-field scale³⁶⁰. For screw mount cameras³⁶⁰.
Variant 2 is a nickel 50mm Elmar in a non-interchangeable mount, without a depth-of-field scale³⁶⁰. This lens focuses to 1.5 feet (0.5 meters). For screw mount cameras³⁶⁰.
Variant 3 is 50mm Elmar in a dial-set Compur shutter and in a fixed mount (as found on Leica I Model B Dial-Set Compur)³⁶⁰. For screw mount cameras and finished in nickel³⁶⁰.
Variant 4 is 50mm Elmar in a rim-set Compur shutter and in a fixed mount (as found on Leica I Model B Rim-set Compur)³⁶⁰. For screw mount cameras and finished in nickel³⁶⁰.
Variant 5 is similar to Variant 3, but with a mount that focuses to 0.5 meters³⁶⁰. For screw mount cameras and finished in nickel³⁶⁰.
Variant 6 is similar to Variant 4, but with a serial number engraved around the lens rim³⁶⁰. This lens is only found on very late Compur Leicas (from the batch starting with serial number 50,000)³⁶⁰. For screw mount cameras and finished in nickel³⁶⁰.
Variant 7 is an interchangeable but unstandardized mount³⁶⁰. Early versions have a five-digit compatibility number, while later versions display a three-digit serial number³⁶⁰. These lenses lack an infinity catch but feature a solid knob with an infinity position at eleven o'clock³⁶⁰. There's also an alignment notch on both the lens and the camera flange. For screw mount cameras and finished in nickel³⁶⁰.
Variant 8 is an uncoupled but with a standardized mount (engraved with “O”); unnumbered, featuring an eleven o'clock infinity lever position³⁶⁰. For screw mount cameras and finished in nickel³⁶⁰.
Variant 9 is coupled, with a standardized mount and an eleven o'clock infinity lever position³⁶⁰. For screw mount cameras and finished in nickel³⁶⁰. One notable modification to the very early Elmars involved a slight adjustment in focal length. The earliest Elmars had focal lengths marginally shorter than 50.0mm. In comparison, after the lenses were designed for interchangeable use on the Leica II Model D in 1932, they averaged about 51.7mm²⁶⁰. The early converted lenses required custom grinding of the rangefinder cam surface, which the rangefinder roller follows during focusing. In contrast, the later lenses with longer focal lengths featured a flatter cam surface. Mr. Barnack had found that the lenses slightly longer than 51mm could focus with the newly introduced Leica II Model D rangefinders without needing the custom grinding of the focusing cam surfaces. In other words, the thread chosen for the focusing mount aligned more precisely with the mechanics of the rangefinder when the lens focal length was slightly longer than 51mm; this allowed for a flatter cam surface, ultimately reducing manufacturing costs²⁶⁰. It is a historical fact that, although the lenses continued to vary slightly in focal length, after 1932, the Elmars were designed with a focal length of 51.68mm, rather than the earlier 49.2mm or 49.5mm²⁶⁰.
Variant 10 is similar to Variant 9, but with a 'bell push' infinity catch³⁶⁰. For screw mount cameras and finished in nickel³⁶⁰.
Variant 11 is similar to Variant 9, but with a 'flat' top infinity catch knob and a seven o'clock locking position³⁶⁰. For screw mount cameras and finished in nickel³⁶⁰.
Variant 12 is similar to Variant 11, but with a locking catch that has a conical top³⁶⁰. For screw mount cameras and finished in nickel³⁶⁰.
Variant 13 is similar to Variant 12, but with a five-digit serial number in early specimens and a six-digit number in later specimens³⁶⁰. For screw mount cameras and finished in nickel³⁶⁰.
Variant 14 is similar to Variant 13, but with an infrared setting on the focusing scale from 1935³⁶⁰. For screw mount cameras and finished in nickel³⁶⁰.
Variant 15 is a lens with a serial number and a standard infinity catch knob³⁶⁰. Finished in chrome³⁶⁰.
Variant 16 is similar to Variant 15, but with infrared marking³⁶⁰. Finished in chrome³⁶⁰.
Variant 17 is similar to Variant 16, but factory-coated starting from serial number 598,201 (1945)³⁶⁰. Finished in chrome³⁶⁰. Some sources indicate a different date and serial number - factory coating is reported to have begun in late 1945, specifically for lenses with serial numbers below 600000²⁶⁰.
Variant 18 is similar to Variant 17, but with an international f-stop scale up to f/16 (later specimens scale up to f/22)³⁶⁰. Finished in chrome³⁶⁰.
Variant 19 is a new lens with an improved optical design, commonly known as the "Red Scale" Elmar starting from serial number 905,000³⁶⁰. Over the years, the basic f/3.5 lens design underwent slight modifications as newer glass types became available, so lenses from different eras may perform somewhat differently. The most significant modification occurred in 1951 with the introduction of rare earth lanthanum glass. This change is believed to have taken place around lens number 905000, although it may have occurred earlier, possibly before serial number 871000²⁶⁰. The Elmars equipped with a black depth of field scale, a minimum aperture of f/22, and serial numbers marked above 871000 from early 1951 until the depth of field scales were changed to red offer the same performance as their red-scale counterparts but are typically available at a significantly lower price²⁶⁰.The lanthanum Elmars eventually earned the nickname "red scale" after the depth of field scale was changed from black to red²⁶⁰.The depth-of-field scale is red, and for the first time, the positions of the focusing and depth-of-field scales are reversed³⁶⁰. Finished in chrome³⁶⁰. The most noticeable difference between the two types of lenses is the color of the depth of field scale. Additionally, the red-scale Elmars feature distance markings on the rotating part of the lens mount and depth markings on the flange. This design allows users to read both distance and depth markings from the top, making the red-scale Elmars somewhat easier to see and use compared to the black-scale lenses, where the distance and depth scales are located around the flange²⁶⁰.Red scale lenses are reported to have serial numbers close to 905000, while black scale lenses can be found with serial numbers well above 1000000. It is theorized that Leitz may have started shipping red scale lenses alongside the new red dial cameras, such as the If, IIf, and IIIf models, whereas black scale lenses were sent separately to match the earlier Black Dial cameras. Regardless of the accuracy of this theory, both versions of the lens were evidently produced simultaneously for a period and offer the same performance. However, red scale lenses currently enjoy more recognition and higher prices, primarily because they are more easily identifiable²⁶⁰.
Variant 20 is finished in black with engravings in white paint³⁶⁰. These lenses were manufactured to match a limited series of black Leica IIIf cameras³⁶⁰.
Variant 21 was recomputed due to the availability of a rare new type of earth glass, resulting in a larger maximum aperture³⁶⁰. The 5cm f/2.8 Elmar now features a click-stop aperture setting and an E39 filter mount³⁶⁰. It is also available with a bayonet mount for models in the M series³⁶⁰. The existence of a prototype for this variant is known³⁶⁰.
Variant 22 is similar to Variant 21, but with a maximum aperture of f/3.5 and available only with a bayonet mount³⁶⁰. For both screw mount and bayonet mount cameras³⁶⁰.

All 5cm Elmar lenses were designed with collapsible mounts. However, there is a prototype 5cm f2.8 lens with a rigid mount (no. 000754) that exists³⁶⁰. The design of this mount is similar to that of the 5cm f/2 Summicron lens³⁶⁰. This prototype was never produced commercially and may have been intended as a basic lens for the M series³⁶⁰.

Additionally, there is a unique specimen of a 5cm f2.8 Elmar lens with a bayonet mount in a Compur shutter, which appears to be the result of an experimental design³⁶⁰.

Conversions from imperial to metric markings, as well as from Continental to international f-stops, were available. As such, in late 1946 or early 1947, the aperture scale on the Elmar was changed from the Continental scale of f/3.5, 4.5, 6.3, 9, etc., to the International scale of f/3.5, 4.5, 5.6, 8, etc., with a minimum aperture of f/16²⁶⁰. Old lenses could also be repolished and coated³⁶⁰.

Some lenses were converted from being mounted on Leica I Model A to a stand-alone lens. A reliable way to identify a Leica I Model A conversion lens is by looking for the inscription "Leitz Elmar 1:3,5 F=50mm" The key detail to note is "F=50mm," as this indicates it is likely a converted lens. In contrast, if the lens is marked "F=5cm", it was designed as an interchangeable lens. This distinction has been consistently observed in every Leica I Model A examined, as well as with the pin release type interchangeable lenses⁵⁹.

Leitz Eigentum lenses

Lenses that circulated within the company's factory or were lent for external use bore the engraving "Leitz Eigentum," meaning "the property of Leitz."³⁶⁰

Military

Some 5cm f3.5 Elmars (around serial numbers 527,000 to 560,000) were supplied to the German military and were engraved with markings such as "Luftwaffen Eigentum," "Heer," and "W. haven."³⁶⁰

Closing Remarks

With a total production exceeding 360,000 units, the 5cm f3.5 Elmar lens is rightly regarded as the quintessential Leica lens³⁶⁰. Remarkably, nearly one in three screw-mounted Leicas left the factory equipped with a 5cm Elmar lens, making it the only high-quality lens manufactured in such large quantities during that period³⁶⁰.

The Elmar 5cm f3.5 lens is considered the quintessential Leica lens, establishing the Leica brand as a serious contender in the camera market³⁶⁰. It remained a favorite even among users of the advanced M models³⁶⁰. Initially, in bayonet mount, it was available with a maximum aperture of either f2.8 or f3.5, but the f3.5 variant was eventually phased out due to declining demand³⁶⁰.

5cm f/2.5 Hektor

Diaphragm adjusting ring for 5cm f/2.5 Hektor is code-named VOOLQ⁸³
The 5cm f/2.5 Hektor appeared first in 1930, initially on non-standardized Leica I Model C's (approximately 1300 of these cameras) and later in standardized mount for the Leica II Model D and onward. It was, for its time, a complex lens with six-element in three groups and a considerably increased speed compared to the 50mm (5cm) f/3.5 Elmar²⁶¹.
The 5cm f/2.5 Hektor was always a small production item and even though it was available until 1949 only about 10000 were made (a mere 3% of the 50mm (5cm) f/3.5 Elmar Production)²⁶¹.

5cm f/2 Summar

5cm f/2 Summar Collapsible lens is code-named SUMUS⁸³ and catalog number 42134²⁷⁵
was produced from 1933-1940²¹⁷
It may be impossible to determine how many of these early Leica lenses were fitted with a black front rim or black nose. The author has documented the "black-nosed" 5cm f/2 Summar collapsible lenses within the following serial number ranges: 167001-168000, 190051-191000, and 192001- 195500²⁸⁷.
The 5cm f/2 Summar Rigid Non-collapsible lens, identified by the code SUMAR, is a rare find. The exact number of these lenses manufactured by Leitz Wetzlar is unknown. It is speculated that many rigid mount lenses were sent back to Leitz for conversion into the 5cm f/2 Summar Collapsible lens. Leitz literature suggests that such conversions were indeed offered. An article in Leica Photography from June 1934 includes a brief mention of this conversion service. This service, available for over 44 years, may help explain the scarcity of the 5cm f/2 Summar Rigid Non-collapsible lenses. The lowest numbered 5cm f/2 Summar Rigid Non-collapsible lens that the writer is aware of is 167014, while the lowest numbered 5cm f/2 Summar Collapsible lens is 167425 (which could possibly be a conversion)⁸⁴.
retained excellent resolving power for enlargements up to and beyond 8 x 10³⁵⁸
diaphragm had stops from f/2 to f/12.5³⁵⁸
The 5cm f/2 Summar Rigid Non-Collapsible lens was introduced in 1933. Following this, the 5cm f/2 Summar Collapsible lens was released in late 1933 or early 1934. This variant of the 5cm f/2 Summar Collapsible lens features the edge of the front rim finished in black paint and is commonly referred to as the black front rim /“black-nosed” 5cm f/2 Summar Collapsible lens. To date, the author has not confirmed the existence of a 5cm f/2 Summar Rigid Non-Collapsible lens with a black front rim/black nose²⁸⁷.

5cm f/1.5 Xenon

The 5cm f/1.5 Xenon lens was introduced in 1936. It has a catalog number 50365, and its code is XEMOO. The lens features an angle of view of 48 degrees and was priced at 213.00 USD at its launch⁷².
There are four known versions of the 5cm f/1.5 Xenon lens: one with a nickel finish, two with chrome, and one that combines nickel and chrome (the latter one being rare). Optical differences exist among these variations⁷².
Leitz soon realized that the lens design infringed on certain patents held by Schneider, which were based on earlier designs developed by the English optical firm Taylor, Taylor, and Hobson. To avoid legal issues⁷⁴, Leitz agreed to license the Xenon name from Schneider while acknowledging Taylor, Taylor, and Hobson patents via engravings on lenses shipped to the United States and the British Empire²²³.
Both U.S. and British patent numbers can be found on the front bezel of the chrome versions of the 5cm f/1.5 Xenon lenses. The U.S. Patent Number 2019985 and the British Patent Number 373950 list Horace William Lee, a British subject, as the inventor and assignor to Kapella, Ltd., a corporation based in Leicester, England. These patents describe a Gauss-type lens featuring a rear element split into two simple components. The U.S. patent was applied for in December 1930, a year before the British patent. The U.S. patent was granted in November 1935, while the British patent was granted in June 1932⁷².
The full capabilities of the 5cm f/1.5 Xenon lens were only realized once an anti-reflection coating was applied. It is constructed as a seven-element lens with ten air-glass surfaces, which renders low contrast in uncoated examples. Illumination is even, but resolution is only sharp in the center when the lens is at full aperture; the sharpness gradually increases as the lens is stopped down. Coated examples at moderate apertures (f/4 to f/9) can display excellent overall resolution and contrast. The lens design led to the development of exceptional postwar high-speed types, such as the Summarit and Summilux⁷².
The 5cm f/1.5 Xenon lens was manufactured from 1936 through 1950, with approximately 6200 units produced⁷².
In May-June 1939, a folding-type lens hood (XIOOM) was introduced, resembling barn doors. It is only 3/8" thick when collapsed, making it easy to slip into a pocket. With a single action, it can spring into its rectangular open position. The design allows for a clear view through the rangefinder and viewfinder, and it does not obstruct the reading or setting of the apertures. The hood can also be folded onto the lens for protection⁷².
Filters for the 5cm f/1.5 Xenon were initially offered in a shiny chrome finish as a 43mm bayonet type, but the black 43mm slip-on type intended for the 7.3cm f/1.9 Hektor can also be used. Additionally, it can accommodate the screw-in E41 type filter. Filters for both the Xenon and Summarit lenses are interchangeable⁷².
A small prototype run was made in 1935 with the serial number starting at 2700XX. It featured a heavy, bright chrome-plated brass mount with a focusing distance of one meter. This heavy mount, combined with the seven glass elements, resulted in a lens that weighed over 300 grams. The prototype series, designated XEMOO, was distinguished by a noticeably crude engraving style on the front element retaining ring, using a font larger than the usual Leitz style. Two finely knurled rings were placed on the rectilinear focusing mount, while a third knurled ring was used for the aperture selector. No patent markings were included on the prototypes²²³.
The first production series began in 1936, presumed to start at serial number 288001 and to consist of approximately 1000 units. The two finely knurled rings on the focusing mount were retained along with the third knurled ring for aperture selection. A smaller font size was introduced on the front element-retaining ring to allow for the required patent information. "DRPa" (Deutsches Reich Patent angemeldet), indicating that the 5cm f/1.5 Xenon lens patent was applied for in Germany, was stamped on all lenses in this series. Approximately the first 200 units in this series featured the f/1.9 and f/2.9 tick marks necessary for the Agfacolor system²²³.
Some Xenon lenses have two black dots on the aperture scale to indicate f/1.9 and f/2.9, intended for use with the older Agfa lenticular color process. Due to constructional limitations, the iris diaphragm can only be stopped down to f/9, as smaller apertures were deemed unnecessary for a lens of this type⁷².
Focusing this heavy lens in difficult conditions was challenging. To improve usability, a third knurled ring was added to the focusing mount between serial numbers 376557 and 376930, resulting in a four-ring design. This change, known as the second major variation of the Xenon, appeared in the last two production batches: serial number 426XXX (1938) and serial numbers from 490XXX to 491XXX (1939 and later).²²³
The final batch included lenses starting around serial number 491500, which were coated on both the external and internal surfaces beginning in 1942. The soft blue coating was easily scratched. Coated lenses were sold in limited quantities until 1950, likely assembled in 1939 but coated later. The lens coating significantly enhanced the Xenon's performance, leading many prewar uncoated lenses to be sent back for postwar coating. Wartime sales exceeded 1000 units, largely driven by military purchases²²³.
Xenon production ceased around serial number 491893, with a total of 6190 units reported based on shipping data from Leitz²²³.
Accessories for Xenon lenses are quite rare. In 1936, a push-on lens hood for the 7.3cm f/1.9 Hektor, designated FGHOO, was suggested. However, vignetting at full aperture led to the introduction of a dedicated lens hood, XIOOM, in 1937, which was specifically designed to clamp onto the lens²²³.
The Xenon hood is uncommon, with variations in engravings. A soft leather case, EXQOO, was produced for storing the lenses, and a brushed chrome front cap labeled XENCA was sold with the lens, but most have been lost. Many Xenon lenses are now paired with the postwar Summarit cap, ORXDO²²³.
Another rare item is a tubular aluminum tropical shipping case, which replaced the standard red cardboard boxes for lenses sent to tropical climates, offering protection against fungus damage during transport²²³.
In 1939, Leitz replaced the plain black filters with bright chrome 40mm push-on filters, which were identical but had new telegraphic codes. A soft leather purse case, labeled EUVAT, was also provided for both Hektor and Xenon filters²²³.

5cm f/2 Summar TROPEN

The 5cm f/2 Summar TROPEN lenses were tested under tropical conditions, characterized by high temperatures and high humidity. Four groups of Summar lenses, labeled “Gruppe I, II, III, or IV,” were documented in the Leica Solms archive²⁷⁵.
Between June and September 1938, lenses from Gruppe I and II were sent to exotic locations such as Bombay, Batavia (now Jakarta), Singapore, and Shanghai, as well as to New York and Italy (likely Genoa). Meanwhile, Gruppe III and IV samples were shipped to the Netherlands, Cuba, and South Africa later in 1938²⁷⁵.
It remains unclear whether all the lenses were identical or if their glass compositions were altered. However, it is certain that in 1938, over 100 5cm f/2 Summar TROPEN lenses were dispatched primarily to tropical destinations. We conclude that the four control groups were assigned to monitor various parameters, including resistance to fungus²⁷⁵.
Catalog number 42214²⁷⁵
The regular 5cm f/2 Summar (Leitz product 42134) features a six-element design, while product 42214 is a seven-element model. A comparison of the cross-sections reveals that the seven-element model includes an extra element at the front of the lens²⁷⁵.
In 1938, Leitz Wetzlar was experimenting with a different Summar design under tropical conditions. The results of this testing and evaluation are unknown to us, and whatever information was gathered from this effort has likely been lost to history following the introduction of the significantly improved 5cm f/2 Summitar (SOORE) later that year²⁷⁵.

5cm f/2 Summitar

a seven-element design which was in design from 1937-39 and was produced from 1939-1955²¹⁷.
A few Summitars were produced in 1953, with a very limited quantity made as late as 1955. The design emphasis of the 1939 Summitar was on achieving the best possible image quality in the central part of the frame at larger apertures, while also providing full frame edge sharpness from about f/3.5 downwards to match the Elmar lens. At the same time, the design aimed to effectively illuminate the corners of the frame at full aperture. To reduce the falloff of illumination at the edges and corners when shooting at large apertures, a large front element was incorporated into the design. This was particularly important for slides made with the high-contrast color transparency films from Kodak and Agfa, which were introduced starting in 1937²⁸⁴.
The Summitar was one of the first Leica lenses to be factory coated. Several coated examples were delivered to the Luftwaffe in 1943. Jim Lager traced two coated Summitars as part of a shipment of 40 that were delivered to the Luftwaffe in August 1943. Postwar Summitars that were commercially available reportedly began to be coated in November 1945. The factory coating significantly enhanced performance at full aperture, improved contrast by eliminating reflections in backlight conditions, and made a lens hood unnecessary even in bright sunlight, except for shading an uncoated filter²⁸⁴.
The construction of this lens was based on the Gauss design but differed in that its front element consisted of two lenses, which enhanced correction capabilities. The lens offered excellent color correction. The designers specifically focused on reducing "vignetting effects," which were the darkening of corners that could occur in images. This aspect was particularly important in the era of color photography. As a result, the front lens of the Summitar was larger in diameter than typically expected. The lens achieved maximum sharpness when stopped down to f/5.6, and it had a wide angle of view³⁵⁸.
Code-named SOORE²⁷⁵

5cm f/1.5 Summarit

production of lens elements was done by Ernst Leitz Canada³¹
code-name SOOIA⁸²
engraved Leitz Canada⁸²
By late 1953, the 5cm f/1.5 Summarit lens was being manufactured at Midland, using metal parts from Canada and lens elements ground from optical glass provided by the German Schott glass works. The Ernst Leitz Canada 5cm f/1.5 Summarit is estimated to have been produced in numbers fewer than 2000, making it highly valued among knowledgeable collectors. Both screw mount and bayonet mount versions of this lens are available¹⁶⁸.
Small Canadian batches recorded include serial numbers 1053XXX, 1246XXX, and 1418XXX. Initially, the Midland plant only assembled lens components that were shipped from Wetzlar. These lenses can be easily identified by the presence of an optical unit marked "Canada," while the focusing mount is engraved with "Germany." This arrangement provided a source of quick cash for the Canadian operations. Eventually, the Midland plant was able to produce all of the required lens components, and these fully Canadian lenses have "Canada" engraved on the focusing mount²²³.
As production of the Summarit continued, advancements in lens coating systems resulted in improved optical performance. Batches of Summarit lenses are recorded with serial numbers 1025XXX, 1052XXX, 1119XXX, 1210XXX, 1332XXX, 1392XXX, 1419XXX, 1500XXX, and 1535XXX. Mechanical enhancements to the Summarit were limited to a redesign of the aperture system in 1957, which first appeared in the 1500XXX batch. This new design featured aperture stops engraved on the rotating aperture selection ring, which rotated around a fixed indicator on the stationary lens barrel. The notched front accessory ring was eliminated with the introduction of this new aperture system, making it impossible to use the bayonet-style accessory filters; instead, they were replaced with chrome 41mm screw-in filters²²³.
The 5cm Summarit f/1.5 was meticulously designed for exceptional clarity, not only at its maximum aperture but also showed an increase in sharpness when stopped down. It replaced the previous 5cm Xenon f/1.5 lens and featured a seven-element optical design that provided outstanding color correction and contrast. Maximum sharpness was achieved at f/4, making the 5cm f/1.5 Summarit not only a high-speed lens suitable for special occasions but also a versatile choice for general photography. It had been corrected for light distribution across the entire field and was free from distortion to a degree that surpassed any prior high-speed lens³⁵⁸.
The lens barrel remained stationary during focusing, which was achieved by turning a knurled grip on the barrel. Due to its large diameter, the barrel was non-collapsible³⁵⁸.
The Summarit lens is equipped with the unique clamping hood known as XOONS, which evolved from the collapsible rectangular hood, XIOOM, originally designed for the Xenon lens. A similar folding hood is preserved in the Leitz Museum²²³.

**5cm f/2 Compur Summitar* Prototype**

In 1951, Leitz New York informed Wetzlar of a special request from a valued customer. This news photographer was using electronic flash equipment with his Leica IIIf Black Dial and expressed concerns about the limitations imposed by the 1/30 second synchronization speed. He requested that a way be developed to achieve electronic flash synchronization at higher shutter speeds.Since the synchronization speed was determined by the design of the basic black dial focal plane shutter, Leitz decided to approach the problem differently. Neurath from the research staff was tasked with integrating a Compur-style between-the-lens shutter into the new 50mm normal lens that was in development. A leaf shutter could provide X-sync at speeds of up to 1/500 second. Neurath succeeded, leading to the creation of the exquisitely rare 5cm f/2 Compur Summitar*. Only six of these prototypes were made, and the serial number range is presumed to be 812301 - 812327. These lenses differ from the usual Summitar* in that they stop down to f/16 instead of f/22¹³⁴.
A special cammed shutter release was required to use the lens at its synchronization speeds of 1/100 and 1/200 of a second. The camera's focal plane shutter was first set to "Bulb," and the special release was pressed to engage the lens operating arm and close the leaf shutter. Continued pressure on the release opened the camera shutter, triggered the leaf shutter, and ultimately allowed the camera's shutter to close. Releasing the pressure on the lever permitted the leaf shutter to open again. A simple adjustment was necessary to calibrate the mechanism for each individual camera. A patent outlining the two-shutter system for flash synchronization at zero delay was applied for and granted in 1955¹³⁴.
None of the original six lenses was sold to the public; after testing, they were returned to the model shop. They were later acquired by privileged Leitz employees. The lenses had the usual superb optical qualities associated with the Summicron, making them quite suitable for general photography. However, new owners typically removed or sawed off the operating arm of the leaf shutter, as it became useless without the shutter release and obstructed the lens's standard operation. As a result, most surviving prototypes are now missing their operating arms¹³⁴.

5cm f/3.5 Elmar Red Scale

Production of the 5cm f/3.5 Elmar Red Scale began in 1951, starting with serial number 905000. It continued until serial number 1812xxx in 1961. Notably, this lens was not introduced to the U.S. market until two years later. The announcement appeared in the Spring 1953 edition of Leica Photography, where the lens was described and featured alongside the If camera. At that time, the lens was only available as part of the If camera (code OEINO) and was priced at 151.30 USD²⁰⁶.
Since its introduction in 1951, most textbooks agree that the diamond design was the first to be used²⁰⁶.

**5cm f/2 Summitar* Prototype**

5cm Summitar 'star' protototype lens, designed in 1950, served as a basis for The 5cm f2 Summicron³⁶⁰.

The Summitar 'star' is similar in design to the standard Summitar but was made using finer rare earth glasses, such as Lanthanum, which are available only in limited quantities³⁶⁰.

This lens is fitted with a 5cm Summitar mount, but it closes the iris at f22, unlike the other variants of the Summitar that close at f12.5 or f16. Inside this modified Summitar mount lies the innovative Summitar 'star' lens, which later became known as the Summicron. While the Summitar 'star' is considered the prototype of the Summicron, only a small number of specimens were produced, starting with the batch numbered 812,000³⁶⁰.

By 1949, a new design had been developed that entered small-scale production as the Summitar. This design was very similar to, but not identical to, the version that went into production in 1953 as the 5cm f/2 Collapsible Summicron²¹⁷.
The change in design from the 5cm f/2 Summitar (1939-1955) to the Summitar was driven by issues with optical glass. At that time, Leitz was using glass that contained radioactive substances and was actively seeking alternatives. The Summitar lenses were produced in two series: 812242 to 812323 and 812341 to 812360²¹⁷.
In 1952, several prototypes of the Summitar lens were issued to notable photographers and members of the Leitz sales staff for field testing and evaluation. These prototypes were based on the Summitar design, leading to their designation as Summitar*. The asterisk was used to indicate a prototype design, and this practice has since become standard procedure at Leitz¹³².
Records from Wetzlar indicate that a total of 79 lenses were produced. The first delivery, part of order No. 73332, was received by export manager Becker on March 3, 1952, and his lens was marked with serial number 812290. Henri Dumur, the Leitz works manager, received lens number 812275. The serial number range for the prototypes was 812242 - 812320. Recipients of these lenses submitted reports back to the design laboratory and typically returned the lenses for further factory testing. This often resulted in the teardown and eventual destruction of the lenses, contributing to the extreme scarcity of the Summitar*. Surviving lenses were later given to privileged employees and eventually made their way into the collector's market¹³².
The prototypes shared many features with the final version of the Summitar. Both featured rectilinear focusing mounts with similar knurling patterns; however, the new lens could be easily identified by its shorter length when extended—37 mm compared to 43 mm for the original Summitar. The new lens had a maximum aperture of f/22, compared to f/16 for the Summitar. However, tests showed that this additional stop was counterproductive, leading to its removal in the production model of the Summicron. All prototypes were engraved with only a meter distance scale¹³².
The optical properties of the 5cm f/2 collapsible Summicron (1953) depended on the special high index of refraction glasses used in its construction. These proprietary glasses were developed by Leitz in the late 1940s and incorporated certain rare-earth elements to achieve the desired optical performance. Initially, thorium oxide was used, which is present in the glass of the prototypes. Thorium is slightly radioactive, so lanthanum oxide—offering similar optical properties—was used in the production 5cm f/2 collapsible Summicron (1953). A Geiger counter can therefore be employed to verify the authenticity of the Summitar*. The lanthanum oxide glasses developed by Leitz for the 5cm f/2 collapsible Summicron (1953) ultimately revolutionized lens design and facilitated significant advancements in optical performance across the industry¹³².

5cm f/2 Collapsible Summicron

Released in 1953¹³²
replaced the 1939-1955 5cm f/2 Summitar¹³²
an improved formula¹³²
seven element modified Gauss formula¹³²
The collapsible Summicron entered production in 1953, but it still contained some radioactive glass elements. However, Leitz developed a replacement glass in its own research lab, known as LaK9. This lanthanum-based optical glass has been sold to Schott and Corning and is still listed in the Schott glass catalogues today. Notably, three of the seven elements in the collapsible Summicron are made of LaK9 glass²¹⁷

5cm f/2 Compur Summicron

In 1951 the 5cm f/2 Summitar* was adapted for use with a built-in Compur shutter, in order to enable the photographer to use electronic flash synchronization at 1/100 or 1/200 sec. An intricately designed arm links the camera shutter releIn 1951, the 5cm f/2 Summitar* lens was modified to include a built-in Compur shutter, allowing photographers to use electronic flash synchronization at speeds of either 1/100 or 1/200 seconds. An intricately designed arm connects the camera's shutter release to the Compur release³⁶⁰.

To use the system, the photographer first sets the camera body shutter to the 'B' mode. When pressure is applied to the top of the release, the camera shutter opens. The photographer then uses another finger to 'fire' the Compur shutter. It is only after this that the camera shutter closes³⁶⁰.

There appear to be two slightly different release arms: one designed for the IIIF model and the other, which is slightly taller, meant for the IIIG model. It is believed that only six specimens, with serial numbers in the 812,000 range, were ever made.ase to the Compur release. The photographer first sets the camera body shutter to B; then he applies pressure to the top of the release, the shutter opens, and with his other finger the photographer 'fires' the Compur shutter. Only then does the release of the camera shutter rise, and the camera shutter close. Two slightly different release arms appear to have been made: the first for use with the IIIF model; the second (slightly higher) for use with the IIIG model. Only six specimens (with serial numbers in the 812,000s) are believed to have been made³⁶⁰.

In 1954, production of the Compur Summicron for Leitz New York began on a special order basis. No catalog code was assigned, although a detailed instruction pamphlet was issued in 1955. Minor changes were made to the leaf shutter, as evidenced by the reversal of the speed sequence engraved on top of the mount. The speed lever was slightly modified to prevent the entry of dust and other foreign matter through the selector slot. The provided shutter release was suitable for the IIIc and IIIf series, with a slightly modified release for the IIIg available after 1957¹³⁴.
The lens was cumbersome to use, as the slowness of the release linkage combined with its unreliability necessitated frequent recalibration, defeating the purpose for which the lens was designed: fast action requiring high-speed flash synchronization. Due to low demand, only a total of 58 units were delivered before production ceased in 1955. Known serial number batches include 1152101-1152150, 1155751-1155800, and 1168601-1168650. The majority of lenses come from the second batch. All possess the optical formula of the 5cm f/2 Summicron, ensuring superb optical performance suitable for conventional photography. As with the prototypes, this has led some owners to remove the operating arm. The low production total and unique design of the Compur Summicron have made it probably the most sought-after and certainly the most expensive collectible among classic Leitz lenses¹³⁴.

5cm f/1.4 Summilux

Code-named SOWGE⁸²
Catalog number 11014⁸⁹
The lens was manufactured between 1960 and 1963, with a total production of 548 units. The serial numbers start at 1717001 - 2015700, and the lens weighs 265 grams⁸⁹.
There is a speculation about second version of this lens. A known sample of the second version has a serial number of 22202XX. This serial number indicates that the lens was produced in 1966, likely during the production period of 1966-1967. Leitz reports that a total of 548 units of the 5cm f/1.4 Summilux were manufactured. Evidence suggests that these are primarily from the first optical design of the 5cm f/1.4 Summilux (SOWGE). Most experts agree that there are no second optical design versions of the 5cm f/1.4 Summilux in existence. However, the author conducted experiments involving light reflected off the lens's internal structure and concluded that, based on the number of elements revealed by this light reflection, the lens in question is indeed a second design¹³⁹.

5cm f/2 Summicron

Code SOSTA¹³⁸
Catalog number 11018¹³⁸
For screwmount cameras¹³⁸
The lens design incorporates special high refractive index glasses infused with trace amounts of rare earth elements and enhanced with special lens coatings. It represents the pinnacle of normal focal length lens designs available for the Leica screwmount camera. The minimum focusing distance is 1 meter, and it features diaphragm click stops up to f/16¹³⁸.
Introduced in 1960, this design remains the standard against which all 50mm screwmount lenses are measured. It was released during the phase-out of the screwmount rangefinder Leica by Leitz, resulting in limited production that lasted only four years, with the last units delivered in 1963. Factory records indicate that a total of 1160 units were produced, making it one of the rarest of the Leitz screwmount lenses. Consequently, it commands a collectible price several times its original price of 150.00 USD¹³⁸.
Accessories for the 5cm Summicron f/2 lens include a lens hood (code IROOA / catalog number 12571), a near-focus attachment compatible with the M series (code SOMKY), and an iris control ring (VTROO) for use with the Focuslide. The push-on lens cap was designated as code ORQDO. Two types of cases were available: a plastic case (code BOOSK) and a leather case (code ETBIX). All E-39 filters can be used with this lens. However, the close-up device for the IIIg (code ADVOO/catalog number 16503) is incompatible with the 5cm Summicron f/2 due to insufficient clearance between the knurled focusing ring of the lens and the accessory-shoe-mounted optical unit of the close-up device for the IIIg¹³⁸.
Reported serial numbers include small batches in the ranges of 1570XXX, 1599XXX, 1704XXX, 1706XXX, 1762XXX, 1763XXX, 1885XXX, and 2181XXX. Units with serial numbers above 1706XXX feature an infrared focusing index. The low and high numbers in this range are of questionable authenticity as they fall outside the accepted manufacturing timeframe. Unfortunately, the collectible value of this rare lens has led to a proliferation of counterfeits¹³⁸.
The rigid focusing mount was available for several years as a replacement part, allowing owners of bayonet lenses to convert them to screwmount by simply switching the optical head between mounts. It is straightforward to unscrew the optical assembly from a bayonet mount and transfer it to a spare screwmount. This transfer can be made virtually undetectable by also switching the small, engraved ring with the lens serial number located behind the optical head of the Summicron. This ring can easily be unscrewed from a bayonet mount and transferred to the screwmount. The switched lens head will function well, provided care is taken to ensure the new mount matches the appropriate focal length group of the optical head. Unfortunately, many conversions have been performed by unscrupulous individuals for monetary gain without regard for focusing accuracy¹³⁸.

50mm f/2 Summicron

Code name 11619³⁵¹
In 1999 or 2000, Leica AG in Solms produced a special edition screw-mount (M39) lens specifically for a Japanese Leica dealer. This lens was made with a bright chrome finish and is mathematically and optically equivalent to its contemporary Leica M counterparts²⁵².
The lens has been produced in bright chrome finish, and is equivalent to its current (at the time) Leica M counterparts mathematically and optically²⁵².
Although the lens was intended exclusively for the Japanese market, not all of them sold, resulting in some being returned to Germany. As shown in the second chart, these rare lenses have significantly increased in value in US dollars. The total number produced remains uncertain, as Leica Camera Company does not disclose this information, and these lenses were never included in the official price catalog²⁵²
The motivation behind producing these screw-mount lenses is also a matter of speculation²⁵²
Length = 42,5mm²⁵²
Weight = 0, 325kg²⁵²
Closest Focusing Distance = 1m²⁵²
Price in October of 2000 = 1962.06 USD and by July of 2001 = 3594.03 USD²⁵²
A total of 980 lenses were produced, with 65 of them shipped to New Jersey²⁵⁶

50mm f/1.4 Summilux

Code-named 11621³⁵⁰
In 1999 or 2000, Leica AG in Solms produced a special edition screw-mount (M39) lens exclusively for a Japanese Leica dealer. This lens features a bright chrome finish and is both mathematically and optically equivalent to its contemporary Leica M counterparts. It also includes built-in telescopic lens hoods, which enhance its usability²⁵².
Originally intended solely for the Japanese market, some of these lenses were returned to Germany because they were not all sold. As shown in the second chart, these rare lenses have significantly appreciated in value (in US dollars). The exact total number of lenses produced is unknown, as the Leica Camera Company does not disclose this information. Furthermore, these lenses were never listed in the official price catalog²⁵².
Comes with built-in lens hood²⁵²
The motivation for producing these screw-mount lenses remains speculative. It is estimated that a total of 1,080 lenses were produced, with 65 of them shipped to New Jersey²⁵².
Length = 45,7mm²⁵²
Weight = 0, 370kg²⁵²
Closest Focusing Distance = 1m²⁵²
Price in October of 2000 = 1962.06 USD and by July of 2001 = 3594.03 USD²⁵²