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 Ernst 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. 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 Model A cameras that it accompanied³⁶⁰.

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. The design of the 50mm (5cm) f/3.5 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 C camera 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 Model D, 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.

Variants

Variant 1 is a nickel 50mm (5cm) f/3.5 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 (5cm) f/3.5 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 (5cm) f/3.5 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 (5cm) f/3.5 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. A source from December of 1930 confirms the serial production of such lenses and that the flange distance of 28.8mm between the lens flange and film plane of Leica I (above serial numbers approximately 60501) was now set³⁶⁴.
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 50mm (5cm) f/3.5 Elmar lenses 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 50mm (5cm) f/3.5 Elmar lenses 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. This variant was introduced in 1933³⁶⁴. After 1936, all lenses of this kind were finished in chrome exclusively³⁶⁴.
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 chrome "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. "Red Scale" Elmar (1951) went the most significant modification with the introduction of rare earth lanthanum glass²⁶⁰. The lanthanum Elmars eventually earned the nickname "red scale" after the depth of field scale was changed from black to red²⁶⁰, and for the first time, the positions of the focusing and depth-of-field scales are reversed³⁶⁰.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. Red scale lenses currently enjoy more recognition and higher prices, primarily because they are more easily identifiable²⁶⁰. Production of the "Red Scale" Elmar 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 Leica If camera. At that time, the lens was only available as part of the Leica If camera (code OEINO) and was priced at 151.30 USD²⁰⁶.
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.

All 50mm (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 f/2.8 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 50mm (5cm) f/3.5 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.

Starting at the end of 1932, lenses with serial number 92201 and above were engraved with externally visible serial numbers³⁶⁴. There is a strong indication that 92201 was a 50mm (5cm) f/3.5 lens³⁶⁴.

Diaphragm adjusting ring for 50mm (5cm) f/3.5 Elmar is code-named VOOLA⁸³ and was developed by Werner Schlapp in 1952, according to a report from February 27, 1952³⁶⁴.

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

In 1939, 49 50mm (5cm) f/3.5 Elmar lenses were delivered to the German military organizations³⁶⁴.

In 1940, 20 50mm (5cm) f/3.5 Elmar lenses were delivered to the German military organizations³⁶⁴.

In 1941, 850 50mm (5cm) f/3.5 Elmar lenses were delivered to the German military organizations³⁶⁴.

In 1942, 215 50mm (5cm) f/3.5 Elmar lenses were delivered to the German military organizations³⁶⁴.

In 1943, 187 50mm (5cm) f/3.5 Elmar lenses were delivered to the German military organizations³⁶⁴.

In 1944, 25 50mm (5cm) f/3.5 Elmar lenses were delivered to the German military organizations³⁶⁴.

Some 50mm (5cm) f/3.5 Elmar lenses (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 50mm (5cm) f/3.5 Elmar lens is rightly regarded as the quintessential Leica lens³⁶⁰. Remarkably, nearly one in three screw-mounted Leicas left the factory equipped with a 50mm (5cm) f/3.5 Elmar lens, making it the only high-quality lens manufactured in such large quantities during that period³⁶⁰.

The 50mm (5cm) f/3.5 Elmar 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 f/2.8 or f/3.5, but the f/3.5 variant was eventually phased out due to declining demand³⁶⁰.

50mm (5cm) f/2.5 Hektor

The 50mm (5cm) f/2.5 Hektor, designed by Max Berek in the late 1920s, features a six-element triplet construction³⁶⁰. It was named after Berek's favorite dog, Hektor³⁶⁰.

In terms of its mount construction, the 50mm (5cm) f/2.5 Hektor was similar to the 50mm (5cm) f/3.5 Elmar and was nearly as compact when collapsed into its draw tube³⁶⁰. Initially, it was provided with a non-interchangeable mount for the Leica I Model A, making that camera essentially a deluxe model since the 50mm (5cm) f/2.5 Hektor was a much faster lens compared to the 50mm (5cm) f/3.5 Elmar³⁶⁰. Only about 1,330 Leica I Model A cameras fitted with the 50mm (5cm) f/2.5 Hektor lens were produced; the lenses themselves were unnumbered, but the cameras were made in isolated batches of one or two (most likely to special order) from serial number 38,622 in 1930 to 71,230 in 1931³⁶⁰.

An announcement from July of 1930 introduced the 50mm (5cm) f/2.5 Hektor lens to the catalog³⁶⁴. Most of the 50mm (5cm) f/2.5 Hektor lenses (originally called 50mm, and later referred to as 5cm) were manufactured between 1930 and 1937, although production continued sporadically until 1946³⁶⁰. It is possible that after 1937, the production of the 50mm (5cm) f/2.5 Hektor was primarily maintained due to the availability of parts and the military's need for lenses, as it was standard practice at Leitz during the war years to utilize all spare parts³⁶⁰. Nevertheless, the total production of the 50mm (5cm) f/2.5 Hektor did not exceed ten thousand— a small number compared to the 360,000 50mm (5cm) f/3.5 Elmar lenses manufactured³⁶⁰. The 50mm (5cm) f/2.5 Hektor was eventually replaced by the faster and more expensive 5cm f2 Summar³⁶⁰.

Variants

Variant 1 was fitted to a Leica I Model A, this variant has no serial number on the lens, a solid catch at the eleven o'clock position, and a depth-of-field scale. It features a nickel finish³⁶⁰.
Variant 2 is unstandardized and uncoupled variant that has an interchangeable mount, a solid catch at the eleven o'clock position, and no serial number, but includes a compatibility number (initially five digits, later three digits) essential for registering the lens to a specific body. It also has a nickel finish³⁶⁰. This variant might have been available since 1931³⁶⁴.
Variant 3 is similar to Variant 2, but this version is standardized and has a '0' engraved on the focusing mount. It features a nickel finish³⁶⁰.
Variant 4 is similar to Variant 3, but is coupled for rangefinder use with a 'bell push' infinity lock at the eleven o'clock position. For the first time, it includes a serial number and a nickel finish³⁶⁰.
Variant 5 follows variant 4 but has a flat-type infinity catch positioned at the seven o'clock position and retains its nickel finish³⁶⁰.
Variant 6 is similar to Variant 5, but has a chrome finish. The poor quality of chrome suggests it may have been produced during wartime³⁶⁰.
Variant 7 is similar to Variant 6, but has "IR" (infrared) marked on the focusing mount. It features a chrome finish³⁶⁰.

Estimating the production numbers for each of these variants is challenging, and it is also unclear whether more lenses with a nickel finish were produced than those with a chrome finish. The 50mm (5cm) f/2.5 Hektor is notable as it was the only non-Elmar-type lens available for the Leica I³⁶⁰.

The lens was listed in the Leitz catalog from 1929 until 1936³⁶¹. Serial numbers ranged from 92301 to 327000³⁶¹. The minimum focusing distance was 100cm³⁶¹. The lens weighs 155 grams³⁶¹.

5cm f/2 Summar

The 5cm f/2 Summar, introduced in 1933, was the first 5cm lens with a maximum aperture of f/2 designed for Leica cameras³⁶⁰. 5cm f/2 Summar comprised six glasses and four elements, and was designed by Max Berek³⁶⁰. Although it was refused a patent in the United States due to its similarity to an existing design, a British patent (no. 423468; 1935) was granted for an f/2 Summar lens with a 100mm focal length, sharing similar computations with the 5cm f/2 Summar³⁶⁰.

The four-element system was based on a telescope lens designed by Carl Gauss³⁶⁴. this design, known as Gauss type, with its many variations, remains the predominant design for 50mm lenses to this day³⁶⁴.

The lens mount was designed by Wilhelm Albert, who also designed two subsequent lenses: 7.5cm f/0.85 Summar and 15cm f/0.85 Summar. Both of these lenses were too expensive to produce in large quantities and were more suitable for scientific rather than general photographic use: the ill-fated 7.5cm f/0.85 Summar (design dated July (or January³⁶⁴) 7, 1937) and the 15cm f/0.85 Summar (dated March 29, 1941). According to records, the latter lens was intended for use by the 'Jäger, Flack, Kriegsmarine' (army, air force, navy)³⁶⁰.

A report dated November 30, 1934, indicates that a lens hood for the 5cm f/2 Summar, resembling the SOOMP lens hood, was developed by Ernst Leitz III and Wilhelm Albert in 1934³⁶⁴.

Variants

The early 5cm f/2 Summars featured a rigid, rotating, non-collapsible mount and a round iris³⁶⁰. Later models were equipped with a non-rotating, collapsible mount and a hexagonal iris to enable compatibility with KDB Agfacolor films³⁶⁰.

Approximately 123,000 Summars were manufactured between 1933 and 1940, peaking at 28,000 units in 1937³⁶⁰. Throughout its seven-year production run, the lens underwent numerous modifications, both major and minor³⁶⁰. The most frequently encountered variants include the following³⁶⁰:

Variant 1 has a rigid mount, rotating, nickel finish; iris scale: f/2 to f/12.5³⁶⁰. The 5cm f/2 Summar Rigid Non-collapsible lens, identified by the code SUMAR, is a rare find⁸⁴. The exact number of these lenses manufactured by Leitz Wetzlar is unknown⁸⁴. 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 offered⁸⁴. An article in Leica Photography from June 1934 includes a brief mention of this conversion service⁸⁴. This service, available for over 44 years, may help explain the scarcity of the 5cm f/2 Summar Rigid Non-collapsible lenses⁸⁴. 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.
Variant 2 is similar to Variant 1, but with an iris scale from f/2 to f/18³⁶⁰.
Variant 3 is similar to Variant 1, but with an all-chrome finish³⁶⁰.
Variant 4 has a collapsible mount; rectilinear nickel finish, with black front rim³⁶⁰. 5cm f/2 Summar Collapsible lens is code-named SUMUS⁸³ and catalog number 42134²⁷⁵. 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.
Variant 5 is similar to Variant 4, but with chrome finish³⁶⁰.
Variant 6 is similar to Variant 4, but with nickel front section³⁶⁰.
Variant 7 is similar to Variant 5, but with chrome front section³⁶⁰.
Variant 8 is similar to Variant 6, but with infra-red marking³⁶⁰.
Variant 9 is similar to Variant 7, but with infra-red marking³⁶⁰.
Variant 10 has a Modified iris scale and control bezel; chrome finish, with infra-red marking³⁶⁰.

It is probable that after the war, some unsold Summar lenses were coated by the factory³⁶⁰. The 5cm f2 Summar is undoubtedly the least appreciated lens from Leitz, primarily due to its inherent softness at full aperture, which is further exacerbated by the fragility of the front element, making it prone to scratches³⁶⁰. Today, it is challenging to find a Summar in immaculate condition, and a fine specimen could prove to be a valuable addition to any collection³⁶⁰.

Closing Remarks

5cm f/2 Summar was produced until 1940²¹⁷. The code name for rigid version was SUMAR and SUMUS for the collapsible³⁶¹. The serial numbers ranged from 167001 through 504500³⁶¹.

5cm f/1.5 Xenon

The Leitz 5cm f/1.5 Xenon (code-named XEMOO³⁶⁰, catalog number 50365⁷²) lens was manufactured in 1936⁷² by Leitz under a license from J. S. Schneider of West Germany, who held the patent rights originally obtained by Taylor, Taylor Hobson for the lens's design³⁶⁰. Since Leitz did not possess the patent rights, they had to produce the lens under the new name, "Xenon."³⁶⁰ Lenses exported by Leitz to the United Kingdom and the United States, where Taylor, Taylor Hobson held the patents, were engraved with the company's initials and patent number³⁶⁰.

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 Xenon features seven lens elements and ten air-to-glass surfaces³⁶⁰. It was introduced in 1935 to satisfy the needs of Leica owners who sought a lens with a speed comparable to the 5cm f/1.5 Sonnar lens that Contax enthusiasts had been using for some time³⁶⁰. Approximately 6,100 Xenons were produced from 1935 to 1939, with an additional 122 units manufactured between 1948 and 1952³⁶⁰. Helmut Lagler noted that Leitz developed the ultra-fast Xenon lens because Leica cameras were widely used by professional photographers, indicating the intended target market³⁶⁴. The same author states that the most sensitive films of that time had ISO ratings around 20 DIN or 50 ASA³⁶⁴.

Prototype

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 units²²³.

Variants

There are two variations in engraving³⁶⁰:

DRPa ("Deutsch Reichspatent Angemeldet," meaning "German patent pending")³⁶⁰
DRP ("Deutsches Reichspatent", meaning "German patent granted"), which appeared from 1938 onwards³⁶⁰.

The most well-known variants are detailed below³⁶⁰:

Variant 1 features settings for f/1.9 and f/2.9, intended for use with the KDB Agfacolor process, which was obsolete by the time the Xenon entered the market³⁶⁰. It includes two knurled rings on the focusing mount and has a chrome finish, along with the Taylor, Taylor Hobson patent number³⁶⁰. 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. Approximately the first 200 units in this series featured the f/1.9 and f/2.9 tick marks necessary for the Agfacolor system²²³.
Variant 2 is similar to Variant 1, but without the aperture indications at f/1.9 and f/2.9, and includes three knurled rings on the focusing mount³⁶⁰. 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. Approximately the first 200 units in this series featured the f/1.9 and f/2.9 tick marks necessary for the Agfacolor system²²³.
Variant 3 includes three knurled rings on the focusing mount, lacks a bayonet filter mount, and features a nose unit slightly longer than that of Variant 2³⁶⁰. The finish is partly chrome, with the front section in nickel³⁶⁰. 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. Also, this variant was likely intended for use with the X-ray Leica³⁶⁰. The Leitz New York X-ray Xenon lens, a modification of Variant 3, was primarily produced for the Westinghouse Corporation³⁶⁰. Another modification, the German Roentgen X-ray Xenon, was designed for use with the German Roentgen X-ray Leica; it focuses permanently at 37 inches, is fitted with a quick-change camera mount, and does not have an iris diaphragm³⁶⁰. A report from May 11, 1939, indicates that Wilhelm Albert developed a Xenon lens with a flat aperture and a new optical formula in 1939³⁶⁴. The author of this website believes that the report refers to Variant 3 of the lens.
Variant 4 is similar to Variant 2 but produced during wartime and coated for enhanced contrast³⁶⁰. 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 contrast⁷². 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.

The lens features an angle of view of 48 degrees and was priced at 213.00 USD at its launch⁷².

Accessories

Accessories for Xenon lenses are quite rare²²³.

A report dated January 7, 1937, indicates that a collapsible folding-type lens hood for the Xenon was developed by Wilhelm Albert in 1937³⁶⁴. 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. The Xenon hood is uncommon, with variations in engravings²²³.

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. A soft leather purse case, labeled EUVAT, was also provided for both Hektor and Xenon filters²²³.

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.

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. In 1939, Leitz replaced the plain black filters with bright chrome 40mm push-on filters, which were identical but had new telegraphic codes²²³.

Closing Remarks

The 5cm f/1.5 Xenon lens production stopped in 1950⁷², around serial number 491893 with a total of 6190 units reported based on shipping data from Leitz²²³. The lens design led to the development of exceptional postwar high-speed types, such as the Summarit and Summilux⁷².

5cm f/2 Summar TROPEN

In 1938, Leitz Wetzlar was experimenting with a different Summar design under tropical conditions²⁷⁵. The 5cm f/2 Summar TROPEN lenses were tested in tropical conditions characterized by high temperatures and high humidity. Four groups of Summar lenses, labeled “Gruppe I, II, III, and IV,” were documented in the Leica Solms archive²⁷⁵. The results of this testing and evaluation are unknown, and any information 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.

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 New York and Italy (likely Genoa). Meanwhile, Gruppe III and IV samples were shipped to the Netherlands, Cuba, and South Africa later in 1938²⁷⁵.

The regular 5cm f/2 Summar (Leitz product 42134) features a six-element design, while product 42214 is a seven-element model²⁷⁵. A comparison of the cross-sections reveals that the seven-element model includes an additional element at the front of the lens²⁷⁵.

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.

5cm f/2 Summitar

The 5cm f2 Summitar (code-named SOORE²⁷⁵), introduced in 1939, replaced the 5cm f2 Summar and was eventually itself succeeded by the 5cm f2 Summicron³⁶⁰. the non-collapsible The 5cm f/2 Summitar lens consists of seven elements, with a large front element measuring 42mm³⁶⁰. It is a development of the 5cm f/2 Summar; the single-glass front element has been replaced with a cemented pair of elements, which minimizes edge fall-off when the lens is used at full aperture due to their increased diameter³⁶⁰. Over 170000 5cm f/2 Summitar lenses were produced between 1938 and 1955²¹⁷, with a peak production of about 28000 units in 1950³⁶⁰. The 5cm f/2 Summitar was particularly favored by users of the newly introduced Kodachrome film, and the color fidelity of the coated 5cm f/2 Summitar is still exceptional even by today’s standards³⁶⁰.

A few 5cm f/2 Summitar lenses were produced in 1953, with a very limited quantity made as late as 1955. The design emphasis of the 1939 5cm f/2 Summitar lens 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 construction of this lens was based on the 7-element³⁶⁴ Gauss design but differed in that its front element consisted of two lenses, which enhanced correction capabilities³⁵⁸. The lens offered excellent color correction³⁵⁸. The designers specifically focused on reducing "vignetting effects," which were the darkening of corners that could occur in images³⁵⁸. This aspect was particularly important in the era of color photography³⁵⁸. As a result, the front lens of the 5cm f/2 Summitar lens was larger in diameter than typically expected³⁵⁸. The lens achieved maximum sharpness when stopped down to f/5.6, and it had a wide angle of view³⁵⁸.

The 5cm f/2 Summitar is regarded as the apex of the 50mm lens design developed by Max Berek³⁶⁴. The rising popularity of color films from Agfa and Kodak, known for their extremely narrow exposure latitude, required lenses that minimized noticeable vignetting in the corners of images³⁶⁴. The Summitar achieved the necessary peripheral brightness for these films through a notably large, cemented front lens³⁶⁴. Additionally, these new lenses were markedly less sensitive to environmental factors, dust, and fingerprints³⁶⁴. The color correction of this new seven-element Gauss variant, which featured three cemented elements and a free-standing lens, approached that of an apochromat³⁶⁴. However, the very large (uncoated) front lens also made the 5cm f/2 Summitar lens particularly prone to stray light³⁶⁴. As a result, Leitz strongly recommended using the relatively large and foldable lens hood that accompanied the lens³⁶⁴.

Prototype

It was reported on March 8, 1933 that the non-collapsible variant of 5cm f/2 Summitar was first developed by Wilhelm Albert in 1933³⁶⁴.

The 50mm f1.5 Summitar, developed during the war, never advanced beyond the prototype stage³⁶⁰. No prototype specimen is available in the Wetzlar museum, and a rumored specimen that may exist elsewhere has not been confirmed³⁶⁰.

Variants

Variant 1 came with a European aperture scale: f2, 2.2, 3.2, 4.5, 6.3, 9, and 12.5; features a conventional round iris made of multiple flat blades; plain rim designed for use with the clamping screw-type folding lens hood (code: SOOPD); chrome finish, uncoated³⁶⁰.
Variant 2 was similar to Variant 1, but with factory coating from November 1945³⁶⁰. The 5cm f/2 Summitar was one of the first Leica lenses to be factory coated²⁸⁴. In fact, it was one of the earliest lenses in the world to feature an anti-reflective coating³⁶⁴. This coating, made from a thin film of magnesium fluoride, was vapor-deposited onto the outer surface of the lenses³⁶⁴. As a result, reflection is minimized, while light transmission and image contrast are enhanced³⁶⁴. Postwar 5cm f/2 Summitar lenses that were commercially available reportedly began to be coated in November 1945²⁸⁴. 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.
Variant 3 came with an international aperture scale: f2, 2.8, 4, 5.6, 8, 11, and 16 (starting from number 611,000)³⁶⁰
Variant 4 was similar to Variant 3, but with a six-blade hexagonal iris diaphragm and a large front groove for attaching a self-locking lens hood (code-named SOOGD); pressure on either side of the hood releases it from the lens. Introduced in 1951³⁶⁰.

Military

The lens was manufactured throughout the war, and many wartime specimens intended for the armed services bear military engravings such as Heer, Luftwaffen Eigentum, and W.H³⁶⁰.

Several coated examples were delivered to the Luftwaffe in 1943. Jim Lager traced two coated 5cm f/2 Summitar lenses as part of a shipment of 40 that were delivered to the Luftwaffe in August 1943²⁸⁴.

In 1940, 553 5cm f/2 Summitar lenses were delivered to the German military organizations³⁶⁴.

In 1941, 119 5cm f/2 Summitar lenses were delivered to the German military organizations³⁶⁴.

In 1942, 116 5cm f/2 Summitar lenses were delivered to the German military organizations³⁶⁴.

In 1943, 59 5cm f/2 Summitar lenses were delivered to the German military organizations³⁶⁴.

Closing Remarks

The production of 5cm f/2 Summitar stopped in 1955²¹⁷.

5cm f/1.5 Summarit

Introduced in 1949, the 5cm f/1.5 Summarit lens (code-named SOOIA³⁶⁰) features a seven-glass construction similar to that of the 5cm f/1.5 Xenon lens, which it replaced. Its design is covered by British patents numbered 373950 and 522651, as well as a United States patent numbered 2019985³⁶⁰. The 5cm f/1.5 Summarit was manufactured in Wetzlar under a license from Taylor, Taylor Hobson. Lenses exported to the United States had patent number details engraved on the lens mount by the Taylor company³⁶⁰.

All Summarit lenses have click-stop apertures and come with factory coatings³⁶⁰. Early models feature a bayonet mount (similar to the 5cm f/1.5 Xenon lens) for lens hoods and filters, while later lenses are equipped with a screw-mount filter thread³⁶⁰. The total production run amounted to approximately 40000 units between 1949 and 1960³⁶⁰.

The screw-mount 50mm f/1.5 Summarit is a coated version of the 50mm f/1.5 Xenon lens³⁶¹. According to factory records, the screw mount 50mm f/1.5 Summarit was manufactured at the Leitz Werke, whereas the last batch was produced in Midland, Canada³⁶¹. The screw mount 50mm f/1.5 Summarit begins its series with serial number 491898, and a total of 102 lenses were allocated (from 491898 - 492000), though it is unclear how many were actually made³⁶¹. The Summarit appears to be identical to the Xenon in all respects, except for the addition of anti-reflection layers as indicated in the factory records³⁶¹.

Small Canadian batches recorded include serial numbers 1053XXX. 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.

A prototype non-folding octagonal hood was developed, featuring two dimples for bayonet attachment to the lens's notched ring, along with a cut-out to avoid obstructing the camera's rangefinder windows. This design also requires precise alignment with the lens for proper function, which led Leitz to favor the XOONS clamping hood while retaining the octagonal shape²²³.

Few bayoneting lens hoods were sold with early lenses with serial numbers 491XXX, making them rare. After the prewar glass was exhausted, a new series with serial number 740XXX was introduced, along with lenses from the 801XXX, 820XXX, and 954XXX batches, all featuring the Taylor, Taylor, and Hobson patent engraving. These markings were discontinued in 1952, with the 999XXX batch being the first without them. Although over 8000 Summarit lenses have these markings, they are sometimes marketed as a rarity²²³.

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 lens²²³. A similar folding hood is preserved in the Leitz Museum²²³. A report from October 17, 1949, suggested that Werner Mohr developed a foldable lens hood for the Summarit in 1949³⁶⁴. The author of this website was unable to confirm the product code.

Variants

Variants of 5cm f/1.5 Summarit are as follows:

Variant 1 has a screw mount; no infrared marking³⁶⁰.
Variant 2 is has a reversed iris scale (marked right to left); features a different style of engraving³⁶⁰.
Variant 3 is same as variant 2, but engraved with "Ernst Leitz Canada Ltd." This variant is very rare³⁶⁰. 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.
Variant 4 is same as variant 3, but with a bayonet mount³⁶⁰.

Closing Remarks

Both screw mount and bayonet mount of 50mm f/1.5 Summarit were produced in significant quantities—75,000 units—and was priced comparably to the dual range variant of the version 2 of 50mm f/2 Summicron, contributing to its commercial success³⁶¹. This popularity may explain the enthusiastic descriptions found in Leitz sales brochures³⁶¹. Production of all Summarit lenses ceased after the introduction of the new 50mm f/1.4 Summilux in 1959. Notably, the prototype 50mm f/1.4 Summilux lenses were marked as "50 / 1.4 Summarit."²²³.

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

The 5cm f/2 Summitar* Prototype lens, developed in 1950, served as the foundation for the 5cm f/2 Summicron lens. This prototype is similar in design to the standard 5cm f/2 Summitar but was crafted using finer rare earth glasses, such as Lanthanum, which are available only in limited quantities³⁶⁰.

In 1952, several 5cm f/2 Summitar* Prototype lenses were given to notable photographers and members of the Leitz sales staff for field testing and evaluation. These prototypes were designated with an asterisk to indicate their prototype status, a practice that has since been adopted as standard procedure at Leitz¹³².

According to records from Wetzlar, a total of 79 5cm f/2 Summitar* Prototype lenses were produced. The first delivery, which was 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 works manager at Leitz, received lens number 812275. The serial number range for the prototypes was 812242 - 812320. Recipients of these lenses provided feedback back to the design laboratory and typically returned the lenses for further factory testing. This process often resulted in the teardown and destruction of the lenses, contributing to the extreme scarcity of the 5cm f/2 Summitar* Prototype lens. Surviving lenses were later awarded to select employees and ultimately found their way into the collector's market¹³².

The 5cm f/2 Summitar* Prototype lens is fitted with a 5cm f/2 Summitar mount but differs from other variants by closing the iris at f/22, while the standard Summitar variants close at f/12.5 or f/16. Within this modified Summitar mount lies the innovative 5cm f/2 Summitar* Prototype lens, which later became known as the 5cm f/2 Summicron. Although the 5cm f/2 Summitar* Prototype lens is considered the precursor to the 5cm f/2 Summicron, only a small number of specimens were produced, starting with the batch numbered 812000³⁶⁰.

The 5cm f/2 Summitar* Prototype lens shares many features with the final version of the 5cm f/2 Summitar, including rectilinear focusing mounts with similar knurling patterns. However, it can be easily identified by its shorter length when extended—37 mm compared to 43 mm for the original 5cm f/2 Summitar. The prototype lens has a maximum aperture of f/22, whereas the standard Summitar has a maximum aperture of f/16. However, tests indicated that this additional stop was counterproductive, resulting in its removal in the production model of the 5cm f/2 Summicron. All prototypes were engraved with only a meter distance scale¹³².

The optical properties of the 5cm f/2 Collapsible Summicron of 1953 relied on a special high index of refraction glass made using proprietary rare-earth elements, developed by Leitz in the late 1940s. Initially, thorium oxide was used, which is present in the glass of the prototypes. As thorium is slightly radioactive, lanthanum oxide—offering similar optical properties—was employed in the production of the 5cm f/2 Collapsible Summicron of 1953. A Geiger counter can be used to verify the authenticity of the 5cm f/2 Summitar* Prototype lens. The lanthanum oxide glasses developed by Leitz for the 5cm f/2 Collapsible Summicron ultimately revolutionized lens design and enabled significant advancements in optical performance across the industry¹³².

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

5cm f/2 Compur Summicron

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. Leitz designer Erwin 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. Leitz designer Erwin 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 5cm f/2 Summitar* Prototype in that they stop down to f/16 instead of f/22¹³⁴.

A special cammed shutter release arm 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.

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 81,000 range, were ever made. 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 close³⁶⁰.

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.

Special Order

In 1954, production of the 5cm f/2 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 5cm f/2 Compur Summicron have made it probably the most sought-after and certainly the most expensive collectible among classic Leitz lenses¹³⁴.

5cm f/2 Collapsible Summicron

The 5cm f/2 Collapsible Summicron (code-named SOOIC) , which incorporates rare earth elements, is designed using a modified seven-glass Gauss optical computation³⁶⁰ . 4 of 7 elements were made of lanthanum glass³⁶⁴. These were thorium-free glasses made from rare earths, which were developed in the Leitz-Werke's own glass research laboratory, created 4 years earlier³⁶⁴.

Since its introduction as a standard model in 1953, it has set high standards for optical quality for many years³⁶⁰ . Two additional models with the same aperture as the 5cm lens, the 3.5cm f2 Summicron and the 9cm f2 Summicron, were released in succession in 1958³⁶⁰ .

The 5cm f2 Summicron is based on a prototype, the 5cm f/2 Summitar* Prototype lens, which was designed in 1950. The 5cm f/2 Summitar* Prototype lens shares a similar optical design with the Summitar but was made using finer rare earth glasses, which are only available in small quantities, such as Lanthanum. It features a 5cm Summitar mount but has an iris that closes to f22, unlike the different variants of the Summitar, which can close to f12.5 or f16. Inside this modified Summitar mount is the groundbreaking 5cm f/2 Summitar* Prototype lens, later known as the Summicron. Although the 5cm f/2 Summitar* Prototype lens is considered the prototype for the 5cm f/2 Collapsible Summicron, very few specimens (starting with serial number 812,000) were actually produced³⁶⁰.

The standard 5cm f/2 Collapsible Summicron features a non-rotating collapsible bayonet mount, a click-stop iris (from f2 to f16, not f22), and an E39 filter mount. Early models have an infrared marking on the focusing scale. From 1953 to 1960, over sixty thousand lenses were manufactured³⁶⁰.

50mm f/2.8 Elmar

The 50mm f/2.8 Elmar lens was a redesigned version of the earlier Elmar 3.5/50 mm³⁶¹. It incorporated new Lanthanum glass, which was also used in the Summicron lens³⁶¹. Although the Leitz designers aimed to improve the lens with this new material, the overall progress was modest³⁶¹. The moving tube for the collapsible mount made the lens mount somewhat unstable, prompting Leitz to create a rigid version that offered significantly better image quality³⁶¹. This elusive Elmarit 1:2.8/50 mm never progressed beyond the prototype stage but had the potential to be an outstanding design³⁶¹.

At maximum aperture, the lens performs reasonably well, although it doesn't deliver results that are particularly exciting³⁶¹. However, performance improves significantly when stopped down, which is typical for many older-generation lenses³⁶¹. The Elmar 2.8/50 mm is notable for its compact size and relatively low price. Pairing an Elmar with a III-series camera—or even better, an M2—results in an aesthetically pleasing combination that was popular among amateur photographers³⁶¹.

In 1957, the price for the Elmar 2.8/50 mm in Germany was DM 198, while the Summicron was priced at DM 380 (and DM 480 for the Summicron NF), highlighting a substantial difference in cost at the time. This lens was quite popular, with a considerable number of units sold³⁶¹.

The lens was listed in the catalogue from 1957-1962 in screw mount³⁶¹. The serial numbers ranged from 1402001 through 2503100 for screw mount and bayonet mount versions³⁶¹. The minimum focusing distance was 100cm³⁶¹. The lens weighs 220 grams and had filter size E39. There were many small changes in engravings and design of the focusing collar³⁶¹.

The screw mount 50mm f/2.8 Elmar with meter scale had catalog number 11512 and was code-named ELMOO³⁶¹.

The screw mount 50mm f/2.8 Elmar with feet scale had catalog number 11012 and was code-named ELMOO³⁶¹.

5cm f/2 Rigid Summicron

5cm f/2 Rigid Summicron (code-named SOSTA, catalog number 11018) for screw mount cameraswas introduced in 1960, this design remains the standard against which all 50mm screwmount lenses are measured¹³⁸.

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 lenses¹³⁸. Consequently, it commands a collectible price several times its original price of 150.00 USD¹³⁸.

The lens design incorporates special high refractive index glasses infused with trace amounts of rare earth elements and enhanced with special lens coatings¹³⁸. The minimum focusing distance is 1 meter, and it features diaphragm click stops up to f/16¹³⁸.

Reported serial numbers include small batches in the ranges of 1570XXX, 1599XXX, 1704XXX, 1706XXX, 1762XXX, 1763XXX, 1885XXX, and 2181XXX¹³⁸. Units with serial numbers above 1706XXX feature an infrared focusing index¹³⁸. The low and high numbers in this range are of questionable authenticity as they fall outside the accepted manufacturing timeframe¹³⁸. Unfortunately, the collectible value of this rare lens has led to a proliferation of counterfeits¹³⁸.

Conversions

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 mounts¹³⁸. It is straightforward to unscrew the optical assembly from a bayonet mount and transfer it to a spare screwmount¹³⁸. 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 Summicron¹³⁸. This ring can easily be unscrewed from a bayonet mount and transferred to the screw mount¹³⁸. 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.

Accessories

Accessories for the 5cm f/2 Rigid Summicron 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 ORQDO¹³⁸. 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 lens¹³⁸. However, the close-up device for the IIIg (code ADVOO/catalog number 16503) is incompatible with the 5cm f/2 Rigid Summicron 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.

5cm f/1.4 Summilux

The 5cm f/1.4 Summilux lens, introduced in 1959, is an ultra-fast seven-element lens that replaced the 5cm f/1.5 Summarit. In terms of optical design, it is a variation of the Summarit and incorporates Lanthanum glass, which reduces flare at large apertures compared to the Summarit. This lens features a non-rotating mount and a click-stop iris mechanism³⁶⁰.

Lenses with serial numbers above 1,844,001 (produced from 1966 onward) underwent recomputation, although the number of elements remained the same³⁶⁰. Production of this lens began in 1959³⁶⁰.

Variants

Variant 1 comes with bayonet mount; chrome finish (from 1959)³⁶⁰. Catalog number 11014⁸⁹.
Variant 2 comes with Screw mount; chrome finish (from 1962)³⁶⁰. Code-named SOWGE⁸².
Variant 3 comes with bayonet mount; finished in black paint to match the black M2, M3, and MP models; likely supplied exclusively with these models or available by special order³⁶⁰.
Variant 4 is recomputed, comes with bayonet mount; black finish (from 1966)³⁶⁰. These lenses had serial numbers above 1,844,001 had the same number of elements despite the recomputation³⁶⁰.
There is a speculation about Variant 5 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 (Variants 1, 2, 3, 4). Most experts agree that there are no second optical design version (Variant 5 of this lens) 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.

50mm f/2 Summicron

In 1999 or 2000, Leica AG in Solms produced a special edition screw-mount 50mm f/2 Summicron lens (catalog number 11619³⁵¹) 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. A total of 980 lenses were produced, with 65 of them shipped to New Jersey²⁵⁶.

The lens has a length of 42.5mm and weight of 0.325kg²⁵². The closest focusing distance is 1m²⁵².

The price in October of 2000 was 1962.06 USD and by July of 2001 increased to 3594.03 USD²⁵².

50mm f/1.4 Summilux

In 1999 or 2000, Leica AG in Solms produced a special edition screw-mount 50mm f/1.4 Summilux lens (catalog number 11621³⁵⁰) 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. 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.

The lens comes with built-in lens hood and has a length of 45.7mm and weight of 0.37kg²⁵². The closest focusing distance is 1m²⁵².

The price in October of 2000 was 1962.06 USD and by July of 2001 increased to 3594.03 USD²⁵².