50MM SCREW MOUNT LENSES

50mm f/3.5 Leitz Anastigmat

In 1923⁵⁴², Max Berek developed a five-element lens, with the three rear elements cemented together, for the "Null-Serie" cameras (starting with number 105³³⁷) and early Leica I Model A cameras²⁶⁰ (numbered 126³⁶⁰ through approximately 250-300⁵⁴²). Although designed by Max Berek, the lens was based on the earlier Anastigmat and was initially named as such due to various pending patents³⁶⁰. 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 finished for Leica I Model A³⁶⁰. Three fine lines were visible on the draw tube of this collapsible lens³⁶⁰. These lines must have aligned 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 collapsible version of 5cm f/2 Summar lens in 1933³⁶⁰.

The "mm" engraving on Anastigmat lenses was placed on the same line as "50"⁵⁷⁵.

50mm f/3.5 Leitz Elmax

After the patents expired, the name of the lens was changed from Anastigmat to Elmax, 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.

The "mm" engraving on Elmax lenses was placed higher than "50"⁵⁷⁵.

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 capabilities³⁵⁸. This allowed for the minimization of both chromatic and monochromatic residual aberrations³⁵⁸. The lens was exceptionally sharp at its maximum aperture and reached peak performance at a diaphragm setting of f/8³⁵⁸. 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 aligned with a built-in rangefinder, making it usable with that feature³⁶⁰. A standardized lens, on the other hand, aligned with the body of any Leica model, though not all standardized lenses were 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.

"Elmar" had been a registered trademark of Leica Camera AG since June 4, 1926⁵³⁴.

The "mm" engraving on Elmar lenses was placed higher than "50" on cameras with serial numbers before 46000, and on the same line as "50" afterwards⁵⁷⁵.

Factory Coating

The factory coating for this lens commenced on April 2, 1946 with serial number 598201⁴⁶¹.

Variants

Variant 1 was 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 included a depth-of-field scale³⁶⁰. For screw mount cameras³⁶⁰.
Variant 2 was a nickel 50mm (5cm) f/3.5 Elmar in a non-interchangeable mount, without a depth-of-field scale³⁶⁰. This lens focused to 1.5 feet (0.5 meters)³⁶⁰. For screw mount cameras³⁶⁰.
Variant 3 was the 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 Compur³⁶⁰. For screw mount cameras and finished in nickel³⁶⁰.
Variant 4 was 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 was similar to Variant 3, but with a mount that focused to 0.5 meters³⁶⁰. For screw mount cameras and finished in nickel³⁶⁰.
Variant 6 was similar to Variant 4, but with a serial number engraved around the lens rim³⁶⁰. This lens was only found on very late Compur Leicas (from the batch starting with serial number 50000)³⁶⁰. For screw mount cameras and finished in nickel³⁶⁰.
Variant 7 was an interchangeable but unstandardized mount³⁶⁰. Early versions had a five-digit compatibility number, while later versions displayed a three-digit serial number³⁶⁰. These lenses lacked an infinity catch but featured a solid knob with an infinity position at eleven o'clock³⁶⁰. There was also an alignment notch on both the lens and the camera flange³⁶⁰. For screw mount cameras and finished in nickel³⁶⁰.
Variant 8 was 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 confirmed the serial production of such lenses and that the flange distance of 28.8mm between the lens flange and film plane of Leica I Model C (above serial numbers approximately 60501) was then set³⁶⁴.
Variant 9 was 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 length²⁶⁰. The earliest 50mm (5cm) f/3.5 Elmar lenses had focal lengths marginally shorter than 50.0mm²⁶⁰. 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 focusing²⁶⁰. In contrast, the later lenses with longer focal lengths featured a flatter cam surface²⁶⁰. 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 surfaces²⁶⁰. 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 was known 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 was similar to Variant 9, but with a 'bell push' infinity catch³⁶⁰. For screw mount cameras and finished in nickel³⁶⁰.
Variant 11 was 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 was similar to Variant 11, but with a locking catch that had a conical top³⁶⁰. For screw mount cameras and finished in nickel³⁶⁰.
Variant 13 was 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 was 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 was 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 was similar to Variant 15, but with infrared marking³⁶⁰. Finished in chrome³⁶⁰.
Variant 17 was similar to Variant 16, but factory-coated starting from serial number 598201 (late²⁶⁰1945)³⁶⁰. Finished in chrome³⁶⁰.
Variant 18 was similar to Variant 17, but with an international f-stop scale up to f/16 (later specimens scale up to f/22)³⁶⁰. And like that, 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.²⁶⁰. Finished in chrome³⁶⁰.
Variant 19 was a new lens with an improved optical design, commonly known as the chrome "Red Scale" Elmar (starting from serial number 905000³⁶⁰). 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 performed somewhat differently²⁶⁰. "Red Scale" Elmar (dated 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 (to make it easier and quicker to read when engaging in synchronized flash photography⁵⁷⁷). Red scale lenses were reported to have serial numbers close to 905000, while black scale lenses could be found with serial numbers well above 1000000²⁶⁰. Production of the "Red Scale" Elmar continued until serial number 1812xxx in 1961²⁰⁶. Notably, this lens was not introduced to the U.S. market until two years later²⁰⁶. The announcement appeared in the Spring 1953 edition of Leica Photography, where the lens was described and featured alongside the Leica If camera²⁰⁶. 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.

Conversions from imperial to metric markings, as well as from Continental to international f-stops, were available³⁶⁰. Old lenses could also be repolished and coated³⁶⁰.

Some lenses were converted from being mounted on Leica I Model A to a stand-alone lens⁵⁹. A reliable way to identify a Leica I Model A conversion lens was by looking for the inscription "Leitz Elmar 1:3,5 F=50mm"⁵⁹. The key detail to note was "F=50mm," as this indicated it was likely a converted lens⁵⁹. In contrast, if the lens was marked "F=5cm", it was designed as an interchangeable lens⁵⁹. This distinction had been consistently observed in every Leica I Model A examined by one author, 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. In fact, Helmut Lagler reports that lens number 92201 was the very first 50mm (5cm) f/3.5 lens⁴³⁹.

Diaphragm adjusting ring for 50mm (5cm) f/3.5 Elmar was 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"³⁶⁰.

Military

In 1939, 49 50mm (5cm) f/3.5 Elmar lenses, with serial numbers ranging from 498887 through 512496, were delivered to the German military organizations³⁶⁴.

In 1940, 20 50mm (5cm) f/3.5 Elmar lenses, with serial numbers ranging from 514029 through 543145, were delivered to the German military organizations³⁶⁴.

In 1941, 850 50mm (5cm) f/3.5 Elmar lenses, with serial numbers ranging from 477984 through 573494, were delivered to the German military organizations³⁶⁴. Some of these were engraved with markings such as "Luftwaffen Eigentum," "Heer," and "W. haven."³⁶⁰

In 1942, 213 50mm (5cm) f/3.5 Elmar lenses, with serial numbers ranging from 534123 through 584099, were delivered to the German military organizations³⁶⁴. Some of these were engraved with markings such as "Luftwaffen Eigentum," "Heer," and "W. haven."³⁶⁰

In 1943, 187 50mm (5cm) f/3.5 Elmar lenses, with serial numbers ranging from 571043 through 593698, were delivered to the German military organizations³⁶⁴.

In 1944, 25 50mm (5cm) f/3.5 Elmar lenses, with serial numbers ranging from 582833 through 593629, were delivered to the German military organizations³⁶⁴.

Post-World War II Prototypes

In his "Geburtstage der Leitz-Foto-Konstruktionen ab 1927" book, Wilhelm Albert credited himself for designing two prototypes of this lens, both attributed to the post-World War II period⁵⁷³:

One prototype had rear aperture reading (described in the book as "Objektiv Elmar 5 cm 1:3,5 mit rückwärtiger Blendenablesung" and dated October 6, 1946)⁵⁷³. The same prototype was illustrated on page 87 of the book⁵⁷³. This lens utilized B268 formula⁵⁷³.
The other prototype had simple straight guide for aperture (described in the book as "Objektiv Elmar 5 cm 1:3,5 mit einfacher Geradführung" and dated November 8, 1946)⁵⁷³. The same prototype was illustrated on page 87 of the book⁵⁷³.

Closing Remarks

With a total production exceeding 360,000 units, the 50mm (5cm) f/3.5 Elmar lens was 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.

50mm (5cm) f/2.5 Hektor

The 50mm (5cm) f/2.5 Hektor, designed by Max Berek in the late 1920s, featured a six-element triplet construction³⁶⁰. It was named after Berek's favourite dog, Hektor³⁶⁰. In his "Geburtstage der Leitz-Foto-Konstruktionen ab 1927" book, Wilhelm Albert dated the "birthday" of the uncoupled version of this lens ("Objektiv Hektor 5 cm 1:2,5 ohne E.-Kupplung") as April 15, 1929, and noted himself as designer⁵⁷³.

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.

An announcement from July 1930 introduced the 50mm (5cm) f/2.5 Hektor lens to the catalogue³⁶⁴. Initially, it was offered with a non-interchangeable mount for the Leica I Model A, making that camera essentially a deluxe model since its lens was a much faster lens compared to the 50mm (5cm) f/3.5 Elmar³⁶⁰. In fact, the 50mm (5cm) f/2.5 Hektor was the only non-Elmar-type lens available for the Leica I Model A³⁶⁰. 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 38622 in 1930 to 71230 in 1931³⁶⁰. Later in 1930, the lens was supplied in an interchangeable but non-standardized mount for the Leica I Model C with non-standardized mount⁵⁴².

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 maintained primarily 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.

The minimum focusing distance was 100cm³⁶¹. The lens weighted 155 grams³⁶¹.

"Hektor" had been a registered trademark of Leica Camera AG since April 25, 1932⁵³⁴.

Variants

Variant 1 was fitted to a Leica I Model A and has no serial number on the lens, a solid catch at the 11 o'clock position, and a depth-of-field scale³⁶⁰. It featured a nickel finish³⁶⁰. This variant was code-named HEKTOR in 1931⁵⁴².
Variant 2 was non-standardized and uncoupled variant with an interchangeable mount, a solid catch at the 11 o'clock position, and no serial number, but included a compatibility number (initially five digits, later three digits) essential for registering the lens to a specific body³⁶⁰. It also had a nickel finish³⁶⁰. This variant might have been available since 1931³⁶⁴. This variant was code-named HEKTOR in 1931⁵⁴². Some examples of this variant had a gold-plated finish⁵⁴².
Variant 3 was similar to Variant 2, but this version was standardized and had a '0' engraved on the focusing mount³⁶⁰. It featured a nickel finish³⁶⁰. This variant was code-named HEKTOR in 1931⁵⁴². Infinity lock was at the 11 o'clock position³⁶⁰. This variant was code-named HEKTOR in 1931⁵⁴².
Variant 4 was similar to Variant 3, but was coupled for rangefinder use, with a 'bell push' infinity lock at the 11 o'clock position, nickel finish³⁶⁰. For the first time, it included a serial number ³⁶⁰. This variant was code-named HEKTORKUP in 1932⁵⁴².
Variant 5 followed variant 4 but had a flat-type infinity catch positioned at the 7 o'clock position and retains its nickel finish³⁶⁰. This variant was code-named HEKTORKUP in 1932⁵⁴². James L. Lager believed that the change from 11 o'clock position to 7 o'clock position happened in late 1932 and early 1933⁵⁴².
Variant 6 was similar to Variant 5, but had a chrome finish³⁶⁰. This variant was code-named HEKTOCHROM in 1933⁵⁴².
Variant 7 was similar to Variant 6, but had "IR" (infrared) marked on the focusing mount. It featured a chrome finish³⁶⁰. The poor quality of chrome suggested it may have been produced during wartime³⁶⁰. This variant could have been code-named HEKTO from 1936⁵⁴².

Estimating the production numbers for each of these variants was challenging, and it was also unclear whether more lenses with a nickel finish were produced than those with a chrome finish³⁶⁰.

Accessories

FIKUS was the recommended lens hood for this lens⁵⁴².

FIKUS variants that had "Hektor" engraved on them could be split into 3 groups⁵⁴²:

The first group of lens hoods were engraved with "Hektor _____ 3,5 Elmar" among other engravings⁵⁴²
The second group of lens hoods were engraved with "Hektor _____ 5" among other engravings⁵⁴²
The third group of lens hoods were engraved with "Hektor _____ 5 Summar" among other engravings⁵⁴²

Closing Remarks

The lens was listed in the Leitz catalogue from 1929 until 1936³⁶¹(or 1939⁵⁴²). Serial numbers ranged from 92301 to 327000³⁶¹. According to one author, 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. According to Helmut Lagler, however, a total of 73220 lenses were produced between 1930 and 1936, with serial numbers ranging from 92301 through 179000⁴³⁹. The 50mm (5cm) f/2.5 Hektor was eventually replaced by the faster and more expensive 5cm f/2 Summar lens³⁶⁰.

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. In his "Geburtstage der Leitz-Foto-Konstruktionen ab 1927" book, Wilhelm Albert dated the "birthday" of the non-retractable version of this lens ("Objektiv Summar 5 cm 1:2 nicht versenkbar") as March 8, 1933, and noted himself as designer⁵⁷³.

5cm f/2 Summar comprised of six elements, and was designed by Max Berek³⁶⁰. The four-element system was based on a telescope lens designed by Carl Gauss³⁶⁴. This design was known as Gauss type³⁶⁴.

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 a 10cm f/2 Summar lens , sharing similar computations with the 5cm f/2 Summar³⁶⁰.

"Summar" had been a registered trademark of Leica Camera AG since November 13, 1936⁵³⁴.

Variants

Variant 1 had a rigid mount, rotating, nickel finish; iris scale³⁶⁰: f/2³⁶⁰ to f/18 on early units and f/12.5 on late ones⁵⁴². This variant was identified by the code SUMAR⁸⁴ or SUMARKUP for its rangefinder coupled versions⁴⁸⁹. This variant had circular opening of the diagram³⁶⁰. It was also known SUMAR with black front rim⁵⁴² numbered 167201 and belonging to a small pre-production batch, was featured in the original illustration of the lens⁴⁸⁹ in November 1933 Leitz literature, which James L. Lager believed to be artist's conception as a sample of this type SUMAR was yet to be located⁵⁴².
Variant 2 was similar to Variant 1, but with an iris scale from f/2 to f/18³⁶⁰on early units and f/12.5 on late ones⁵⁴².
Variant 3 was similar to Variant 1, but with an all-chrome finish³⁶⁰. The code name for this variant was SUMARCHROM⁴⁸⁹.
Variant 4 had a collapsible mount; rectilinear nickel finish, with black front rim³⁶⁰. This variant was code-named SUMUS⁸³ and had catalog number 42134²⁷⁵. It was impossible to determine how many of these early Leica lenses were fitted with a black front rim²⁸⁷. One author documented the collapsible lenses with black front rim within the following serial number ranges: 167001-168000, 190051-191000, and 192001- 195500²⁸⁷. This variant, dated late 1933-early 1934⁵⁴², had a hexagonal opening of the diagram and non-rotating mount⁵⁴²to enable compatibility with KDB Agfacolor films³⁶⁰. Early examples of this variant were engraved with a special mark at f/2.9 to accommodate the use of specific filters designed for Agfacolor film⁵⁴². Some of the lenses that had the f/2.9 mark also had a protruding coupling tab beneath the f/2.9 mark, while others did not⁵⁴².
Variant 5 was similar to Variant 4, but with chrome finish³⁶⁰, code-named SUMUS CHROM⁴⁸⁹.
Variant 6 was similar to Variant 4, but with nickel front section³⁶⁰.
Variant 7 was similar to Variant 5, but with chrome front section³⁶⁰.
Variant 8 was similar to Variant 6, but with infra-red marking³⁶⁰. Serial numbers starting 240XXX, around 1935⁴⁸⁹.
Variant 9 was similar to Variant 7, but with infra-red marking³⁶⁰. Serial numbers starting 240XXX, around 1935⁴⁸⁹.
Variant 10 has a modified iris scale and control bezel; chrome finish, with infra-red marking³⁶⁰. Around serial number 2397XX⁴⁸⁹.
Variant 11 was a later variant from 1937-1939 has no index mark at f/2.9 because by this time the lenticular Agfacolor process has been replaced⁴⁸⁹. The examples of this variant were in serial number range of 37970X-48269X⁴⁸⁹.

It was probable that after the war, some unsold 5cm f/2 Summar lenses were coated by the factory³⁶⁰. The 5cm f/2 Summar lens was undoubtedly the least appreciated lens from Leitz, primarily due to its inherent softness at full aperture, which was further exacerbated by the fragility of the front element, making it prone to scratches³⁶⁰. Today, it is challenging to find a 5cm f/2 Summar in immaculate condition, and a fine specimen could prove to be a valuable addition to any collection³⁶⁰.

Conversion From Rigid to Collapsible

The exact number of the rigid 5cm f/2 Summar lenses manufactured by Leitz Wetzlar was unknown⁸⁴. According to James L. Lager's research and factory records, there were less than 2000 rigid mount lenses manufactured⁵⁴². Most examples of the rigid variant had serial numbers in the range 180000-190000 (especially from 1862XX through 1869XX) and with just a few examples over 200000⁴⁸⁹. It was speculated that many of the rigid mount lenses were sent back to Leitz for conversion into the 5cm f/2 Summar Collapsible lens⁸⁴. Leitz literature suggested that such conversions were indeed offered⁸⁴. An article in Leica Photography from June 1934 included a brief mention of this conversion service⁸⁴. This service, available for over 44 years, might help explain the scarcity of the rigid 5cm f/2 Summar lenses⁸⁴. The lowest numbered rigid 5cm f/2 Summar lens that one researcher was aware of was 167014, while the lowest numbered 5cm f/2 Summar Collapsible lens was 167425 (which could possibly be a conversion)⁸⁴.

Lens Hoods

FIKUS lens hood was used for the rigid variant (SUMAR)⁵⁴². Some FIKUS lens hood were engraved with "Hektor _____ 5 Summar" among other engravings⁵⁴².

Rectangular SOOMP lens hood was used for the collapsible variant (SUMUS)⁵⁴². A report dated November 30, 1934, indicated that a lens hood resembling the SOOMP lens hood, was developed by Ernst Leitz III and Wilhelm Albert in 1934³⁶⁴.

Ernst Leitz, New York, produced the SOOMP lens hood in chrome or black finishes, which displayed various styles and placements of engravings⁵⁴². Some SOOMP produced by Ernst Leitz, New York, came in military packaging⁵⁴².

Schmidt Tokyo produced a lens hood for the collapsible variant (SUMUS) in style similar to that of Leitz lens hoods made for 5cm f/1.5 Xenon and 5cm f/2 Summitar lenses⁵⁴². This lens hood was engraved "Summar <new line> Schmidt Shoten Tokyo"⁵⁴².

Filters

Agfa system projection filter for 5cm f/2 Summar lenses was code-named FOOPX⁵⁴².

Agfa system exposure filters for 5cm f/2 Summar lenses were code-named FOOSM and KUEOO⁵⁴².

In Literature

Collapsible SUMUS variant was featured in the famous 1935 CAT's EYE LEICA advertisement⁵⁴².

Closing Remarks

Approximately 123,000 5cm f/2 Summar lenses were manufactured between 1933³⁶⁰ and 1939⁵⁴²(or 1940²¹⁷), peaking at 28,000 units in 1937³⁶⁰. The serial numbers ranged from 167001 through 504500³⁶¹. According to Helmut Lagler, however, overall, there were 766440 lenses produced between 1933 and 1936, with serial numbers ranging from 167001 through 503600⁴³⁹.

Other Summar Lenses - 7.5cm f/0.85 Summar and 15cm f/0.85 Summar

The lens mount was designed by Wilhelm Albert, who also designed two subsequent lenses³⁶⁰: the 7.5cm f/0.85 Summar and the 15cm f/0.85 Summar lenses:

Non-military variant of 7.5cm f/0.85 Summar lens - In his "Geburtstage der Leitz-Foto-Konstruktionen ab 1927" book, Wilhelm Albert dated the "birthday" of this 7.5cm f/0.85 Summar lens ("Objektiv Summar f=7,5 cm 1:0,85") as January 7, 1937, and noted himself as designer⁵⁷³. This lens was not identified as "Kriegsgeräte" (military equipment) in the book⁵⁷³.
Military variant of 7.5cm f/0.85 Summar lens - In his "Geburtstage der Leitz-Foto-Konstruktionen ab 1927" book, Wilhelm Albert dated the "birthday" of the 7.5cm f/0.85 Summar lens with auxiliary lens for 37,5 cm object distance 100 x 100 and OLEYO auxiliary camera ("Objektiv Summar f=7,5 cm 1:0,85 mit Vorsatzlinse für 37,5 cm Objektabstand 100x100 und Hilfskamera OLEYO") as August 1, 1940, and noted himself as designer⁵⁷³.This lens was identified as "Kriegsgeräte" (military equipment) in the book⁵⁷³.
Military variant of the IR (infrared) 15cm f/0.85 Summar lens - In his "Geburtstage der Leitz-Foto-Konstruktionen ab 1927" book, Wilhelm Albert dated the "birthday" of the IR (infrared) 15cm f/0.85 Summar lens without sight (scope?) ("IR Summar Objektiv f=15 cm 1:0,85 ohne Visier (für Jäger, Flak und Kriegsmarine") as March 29, 1941, and noted himself as designer⁵⁷³. This lens was identified as "Kriegsgeräte" (military equipment) in the book and was destined for use by army, air force and navy⁵⁷³.

All three of these lenses were too expensive to produce in large quantities and were more suitable for scientific and military rather than general photographic use³⁶⁰.

Some known examples:

One 7.5cm f/0.85 Summar without serial number and dated "circa 1940" was sold for 4800 Euros including buyer's premium at the 41st Leitz Photographica Auction on November 26, 2022³⁸². The lot description read: "famous, ultra-fast lens made by Leitz, designed in 1935 for X-ray photography, here in uncommon version, used during WWII by the German army for thermal imaging in Spanner devices..."³⁸².
15cm f/0.85 Sumar (Spanner) with serial number 573131 was part of German collection in August of 2026. It was auctioned off at the Auction Team Breker at some point in time.
75mm f/0.85 Summar with serial number 582284, dated 1941, was described by Chris Kok on Page 46 of Viewfinder, Volume 32, Number 3, 1999. It featured a short, vented hood that was permanently affixed to the front of the lens and included its own focusing barrel. This particular lens was not coated and lacked an aperture diaphragm. Externally, it appeared different from the examples shown in Lager's "Leica Illustrated History Volume II - Lenses" (page 129) and Scheever and Makovec's "The Leica and the Leicaflex" (pages 61 and 62). The latter book also mentioned that this extremely fast lens was used for special applications, such as X-ray screen photography. It was also noted that during the 1936 Olympic Games, the lens was utilized in the projection room of the German postal authorities for projecting television images.
15cm f/0.85 Sumar (Spanner) with serial number 594652 and dated 1943 was sold for 2400 Euros including buyer's premium at the 32nd WestLicht Camera Auction on March 10, 2018³⁹¹. The lot was described as "very rare huge ultra-fast beige painted lens for German military used in WWII (as a part of a target tracking device, used for example on the Dornier Do 17 surveillance planes), only few of these impressive lenses are still existing, breech-lock mount, slightly hazy optics with some small scratches, with original front protective cap and wooden case - this lens (Sumar 15 cm 1:0.85) was delivered on January 29th, 1944 to AGG Bln.2442"³⁹¹.
15cm f/0.85 Sumar (Spanner) with serial number 594671 and dated 1943 was sold for 13200 Euros including buyer's premium at the 24th WestLicht Camera Auction on November 23, 2013⁴⁰⁰. The lot was described as "ultra-fast beige painted lens for military use in WWII, original front cap and wooden storage box"⁴⁰⁰.

5cm f/1.5 Xenon

In his "Geburtstage der Leitz-Foto-Konstruktionen ab 1927" book, Wilhelm Albert dated the "birthday" of the 5cm f/1.5 Xenon with "dome" aperture ("Objektiv Xenon 5 cm 1:1,5 mit Kuppelblende") as July 30, 1935, and noted himself as designer⁵⁷³.

The Leitz 5cm f/1.5 Xenon (code-named XEMOO³⁶⁰, catalog number 50365⁷²) lens was introduced in 1935³⁶⁰ and manufactured in July⁴⁷⁶ 1936⁷² (starting with 288001²²³) by Leitz under a license from Joseph Schneider of West Germany, who held the patent rights originally obtained by Taylor, Taylor Hobson for the lens design³⁶⁰. Since Leitz did not possess the patent rights, they had to produce the lens under the new name, "Xenon"³⁶⁰.

The 5cm f/1.5 Xenon featured seven lens elements and ten air-to-glass surfaces³⁶⁰. It was introduced 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. Helmut Lagler noted that Leitz developed the ultra-fast 5cm f/1.5 Xenon lens because Leica cameras were widely used by professional photographers at the time when the most sensitive films of that time had ISO ratings around 20 DIN or 50 ASA³⁶⁴. The lens featured an angle of view of 48 degrees and was priced at 213.00 USD at the time of the launch⁷².

Patent Engravings

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: 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, England⁷². These patents describe a Gauss-type lens featuring a rear element split into two simple components⁷². The U.S. patent was applied for in December 1930, a year before the British patent⁷². The U.S. patent was eventually granted in November 1935, while the British patent was granted in June 1932⁷².

The lenses were also engraved "D.R.P.a" (Deutsches Reich Patent angemeldet (applied for))⁵⁴². It was known that some lenses (like the very early one numbered 288015) did not feature any engravings or had only "D.R.P.", the German patent engraving⁵⁴². This latter engraving was present on lenses manufactured from 1938 onwards³⁶⁰. These lenses were believed to be marketed to non-U.S and non-British markets⁵⁴².

Prototype

A small prototype run was made in 1935 with the serial number starting at 2700XX²²³. It featured a heavy, bright chrome-plated brass mount with a focusing distance of one meter²²³. This heavy mount, combined with the seven glass elements, resulted in a lens that weighed over 300 grams²²³. 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 style²²³. Two finely knurled rings were placed on the rectilinear focusing mount, while a third knurled ring was used for the aperture selector²²³. No patent markings were included on the prototypes²²³.

One such prototype, 270004, dated 1935, was in the Leica GmbH Solms museum at some point in time⁵⁴². The photograph of this lens was featured on page 44 of James L. Lager's "Leica: An Illustrated History - Volume 2 - Lenses - Signed Deluxe Limited Edition" book⁵⁴². It was also illustrated in Mr. Lars Netopil's "Museum Leica" book in 2018⁵⁹⁶.

Variants

Variant 1 was a prototype and had:

1 knurled aperture ring and 2 focusing rings (3 in total)
chrome finish
black front ring surrounding the front element
had aperture values of 1.5, 1.6, 2.2, 3.2, 4.5, 6.3, 9
featured indexing marks for f/1.9 and f/2.9, intended for use with the KDB Agfacolor process, which was obsolete by the time the 5cm f/1.5 Xenon entered the market³⁶⁰. Approximately the first 200 units had marks both on f/1.9 and f/2.9²²³.
"Feet Germany" engraving on the scale ring
no engraving on the closest ring to the lens mount
"Taylor-Hobson British Patent 373950 and U.S.Patent 2019985 Leitz Xenon f=5cm 1:1,5 Nr. (no serial number)" engraved on the front ring
"Ernst Leitz Wetzlar" engraved on the barrel
for American and British market⁵⁴²

Variant 2 had:

1 knurled aperture ring and 2 focusing rings (3 in total)
chrome finish
black front ring surrounding the front element
had aperture values of 1.5, 1.6, 2.2, 3.2, 4.5, 6.3, 9
featured indexing marks for f/1.9 and f/2.9, intended for use with the KDB Agfacolor process, which was obsolete by the time the 5cm f/1.5 Xenon entered the market³⁶⁰. Approximately the first 200 units had marks both on f/1.9 and f/2.9²²³.
"Feet Germany" engraving on the scale ring
no engraving on the closest ring to the lens mount
"D.R.P.a. Taylor-Hobson U.S.Pat.2019985 Leitz Xenon f=5cm 1:1,5 № XXXXXX" engraved on the front ring
"Ernst Leitz Wetzlar" engraved on the barrel
for American market⁵⁴²
"D.R.P.a." stood for "Deutsches Reich Patent angemeldet" (i.e. "applied for")⁵⁴²

Variant 3 had:

1 knurled aperture ring and 2 focusing rings (3 in total)
nickel finish
black front ring surrounding the front element
had aperture values of 1.5, 1.6, 2.2, 3.2, 4.5, 6.3, 9
featured indexing marks for f/1.9 and f/2.9, intended for use with the KDB Agfacolor process, which was obsolete by the time the 5cm f/1.5 Xenon entered the market³⁶⁰. Approximately the first 200 units had marks both on f/1.9 and f/2.9²²³.
"Feet Germany" engraving on the scale ring
no engraving on the closest ring to the lens mount
"D.R.P.a. Taylor-Hobson British Patent 373950 and U.S.Patent 2019985 Leitz Xenon f=5cm 1:1,5 № XXXXXX" engraved on the front ring
"Ernst Leitz Wetzlar" engraved on the barrel
for American and British markets⁵⁴²
"D.R.P.a." stood for "Deutsches Reich Patent angemeldet" (i.e. "applied for")⁵⁴²
Examples included 288866 dated 1936⁴⁰³, 376460 dated 1937⁴¹⁵.

Variant 4 had:

1 knurled aperture ring and 2 focusing rings (3 in total)
chrome finish
black front ring surrounding the front element
had aperture values of 1.5, 1.6, 2.2, 3.2, 4.5, 6.3, 9
without index marks at f/1.9 and f/2.9 for Agfa color film process
"Feet Germany" engraving on the scale ring
no engraving on the closest ring to the lens mount
"D.R.P.a. Taylor-Hobson British Patent 373950 and U.S.Patent 2019985 Leitz Xenon f=5cm 1:1,5 № XXXXXX" engraved on the front ring
"Ernst Leitz Wetzlar" engraved on the barrel
for American and British markets⁵⁴²
"D.R.P.a." stood for "Deutsches Reich Patent angemeldet" (i.e. "applied for")⁵⁴²

Variant 5 had:

1 knurled aperture ring and 3 knurled rings on the focusing mount (4 in total). Focusing with only 2 knurled rings on the focusing mount of this heavy lens in difficult conditions was challenging²²³. To improve usability, a third knurled ring was added to the focusing mount between serial numbers 376557 and 376930, resulting in a four-ring design²²³. This variant lacked a bayonet filter mount, and featured a nose unit slightly longer than that of variants with 2 knurled rings on the focusing mount³⁶⁰.
chrome finish
black front ring surrounding the front element
had aperture values of 1.5, 1.6, 2.2, 3.2, 4.5, 6.3, 9
without index marks at f/1.9 and f/2.9 for Agfa color film process
"mtr" engraving on the scale ring
no engraving on the closest ring to the lens mount
"D.R.P.a. Taylor-Hobson British Patent 373950 and U.S.Patent 2019985 Leitz Xenon f=5cm 1:1,5 № XXXXXX" engraved on the front ring
"Ernst Leitz Wetzlar" engraved on the barrel
for American and British markets⁵⁴²
"D.R.P.a." stood for "Deutsches Reich Patent angemeldet" (i.e. "applied for")⁵⁴²

Variant 6 had:

1 knurled aperture ring and 2 knurled rings on the focusing mount (3 in total)
chrome finish
black front ring surrounding the front element
had aperture values of 1.5, 1.6, 2.2, 3.2, 4.5, 6.3, 9
without index marks at f/1.9 and f/2.9 for Agfa color film process
"mtr" engraving on the scale ring
no engraving on the closest ring to the lens mount
"D.R.P. Leitz Xenon f=5cm 1:1,5 № XXXXXX" engraved on the front ring
"Ernst Leitz Wetzlar" engraved on the barrel
for non-American and non-British markets⁵⁴²

Variant 7 had:

1 knurled aperture ring and 2 knurled rings on the focusing mount (3 in total)
chrome finish
chrome front ring surrounding the front element
had aperture values of 1.5, 1.6, 2.2, 3.2, 4.5, 6.3, 9
without index marks at f/1.9 and f/2.9 for Agfa color film process
"mtr" engraving on the scale ring
no engraving on the closest ring to the lens mount
"D.R.P. Leitz Xenon f=5cm 1:1,5 № XXXXXX" engraved on the front ring
"Ernst Leitz Wetzlar" engraved on the barrel
for non-American and non-British markets⁵⁴²
At least two lenses were known with chrome front rings, one of which had serial number 426397 and was featured in Jo Geier's video titled "Leica Beyond Production ". Other one was numbered 376074 and was sold by Coeln Cameras. One more, number 289548 was part of a European collection in September of 2026.

Variant 8 had:

1 knurled aperture ring and 2 knurled rings on the focusing mount (3 in total)
chrome finish
black front ring surrounding the front element
had aperture values of 1.5, 1.6, 2.2, 3.2, 4.5, 6.3, 9
without index marks at f/1.9 and f/2.9 for Agfa color film process
"mtr" engraving on the scale ring
"Germany" engraved on the closest ring to the lens mount
"D.R.P. Leitz Xenon f=5cm 1:1,5 № XXXXXX" engraved on the front ring
"Ernst Leitz Wetzlar" engraved on the barrel
for non-American and non-British markets⁵⁴²

Variant 9 had:

1 knurled aperture ring and 3 knurled rings on the focusing mount (4 in total). Focusing with only 2 knurled rings on the focusing mount of this heavy lens in difficult conditions was challenging²²³. To improve usability, a third knurled ring was added to the focusing mount between serial numbers 376557 and 376930, resulting in a four-ring design²²³. This variant lacked a bayonet filter mount, and featured a nose unit slightly longer than that of variants with 2 knurled rings on the focusing mount³⁶⁰.
chrome finish
black front ring surrounding the front element
had aperture values of 1.5, 1.6, 2.2, 3.2, 4.5, 6.3, 9
without index marks at f/1.9 and f/2.9 for Agfa color film process
"mtr" engraving on the scale ring
no engraving on the closest ring to the lens mount
"D.R.P. Leitz Xenon f=5cm 1:1,5 № XXXXXX" engraved on the front ring
no engravings on the barrel
for non-American and non-British markets⁵⁴²

Variant 10 had:

1 knurled aperture ring and 3 knurled rings on the focusing mount (4 in total). Focusing with only 2 knurled rings on the focusing mount of this heavy lens in difficult conditions was challenging²²³. To improve usability, a third knurled ring was added to the focusing mount between serial numbers 376557 and 376930, resulting in a four-ring design²²³. This variant lacked a bayonet filter mount, and featured a nose unit slightly longer than that of variants with 2 knurled rings on the focusing mount³⁶⁰.
chrome finish
black front ring surrounding the front element
had aperture values of 1.5, 1.6, 2.2, 3.2, 4.5, 6.3, 9
without index marks at f/1.9 and f/2.9 for Agfa color film process
"mtr" engraving on the scale ring
no engraving on the closest ring to the lens mount
"D.R.P. Leitz Xenon f=5cm 1:1,5 № XXXXXX" engraved on the front ring
"Ernst Leitz Wetzlar" engraved on the barrel
for non-American and non-British markets⁵⁴²

Variant 11 was military issue / X-ray application, had a heavy front rim, and:

1 knurled aperture ring and 3 knurled rings on the focusing mount (4 in total). Focusing with only 2 knurled rings on the focusing mount of this heavy lens in difficult conditions was challenging²²³. To improve usability, a third knurled ring was added to the focusing mount between serial numbers 376557 and 376930, resulting in a four-ring design²²³. This variant lacked a bayonet filter mount, and featured a nose unit slightly longer than that of variants with 2 knurled rings on the focusing mount³⁶⁰.
chrome finish with nickel front rim and aperture control ring
nickel/chrome front ring surrounding the front element
had aperture values of 1.5, 2.2, 3.2, 4.5, 6.3, 9
without index marks at f/1.9 and f/2.9 for Agfa color film process
"mtr" engraving on the scale ring
no engraving on the closest ring to the lens mount
"Ernst Leitz Wetzlar Xenon f=5 cm 1:1,5 No XXXXXX" engraved on the front ring, with "o" after "N" positioned on the same line as "N".
no engravings on the barrel
lenses number 376950 dated 1943³⁸², 490482 dated 1939³⁸⁶, 491276⁵⁴², 491579⁵⁴² were examples of this variant.
The Leitz New York X-ray Xenon lens (from early 1940s⁵⁴²) was primarily produced for the Westinghouse Corporation³⁶⁰. Another modification, the German Roentgen X-ray Xenon lens (RDXOO⁵⁴²) from approximately 1940-1944⁵⁴², was designed for use with the German Roentgen X-ray Leica (RUXOO⁵⁴²); it focused permanently at 37 inches, is fitted with a quick-change camera mount, and did not have an iris diaphragm³⁶⁰. In his "Geburtstage der Leitz-Foto-Konstruktionen ab 1927" book, Wilhelm Albert dated the "birthday" of the "flat" aperture (new optics) version of this lens ("Objektiv Xenon 5 cm 1:1,5 mit Planblende (neue Optik)") as May 11, 1939, and noted himself as designer⁵⁷³.
Some lenses were used for measurement of projectile velocity⁵⁷³. As such, in his "Geburtstage der Leitz-Foto-Konstruktionen ab 1927" book, Wilhelm Albert dated the "birthday" of 5cm f/1.5 Xenon lens with insulation protection for barrier cell and auxiliary camera for projectile velocity measurement ("Xenon Objektiv f=5cm 1:1,5 mit Isolationsschutz für Sperrzelle und Hilfskamera (Geschoßgeschwindigkeitsmessung)") as March 15, 1942, and noted himself as designer⁵⁷³. This lens was identified as "Kriegsgeräte" (military equipment) in the book and had black rim around front element (possibly for aperture control), with a serial number engraved on it⁵⁷³. Example of the lens illustrated in the book was number 376944 ⁵⁷³.
5cm f/1.5 Xenon lenses produced during wartime were coated for enhanced contrast³⁶⁰. The full capabilities of the lens were realized once anti-reflection coating was applied⁷². It was constructed as a seven-element lens with ten air-glass surfaces, which rendered low contrast in uncoated examples⁷². Coated examples at moderate apertures (f/4 to f/9) could display excellent overall resolution and contrast⁷². It was known that the final batch included lenses starting around serial number 491500, which were coated on both the external and internal surfaces beginning in 1942²²³. The soft blue coating was easily scratched²²³. Coated lenses were sold in limited quantities until 1950, with many likely assembled in 1939, but coated later²²³.
Wartime sales exceeded 1000 units, largely driven by military purchases²²³.

Accessories

Accessories for 5cm f/1.5 Xenon lenses were quite rare²²³.

A report dated January 7, 1937, indicated that a collapsible folding-type lens hood for the 5cm f/1.5 Xenon was developed by Wilhelm Albert in 1937³⁶⁴. In May-June 1939 (or in late 1938⁵⁴²), a folding-type lens hood (XIOOM) was introduced, resembling barn doors⁷². It was only 3/8" thick when collapsed, making it easy to slip into a pocket⁷². With a single action, it could spring into its rectangular open position⁷². The design allowed for a clear view through the rangefinder and viewfinder, and it did not obstruct the reading or setting of the apertures⁷². The hood could also be folded onto the lens for protection⁷². The Xenon hood is uncommon, with variations in engravings²²³. 1937 Leitz literature suggested that FGHOO lens hood made for the 7.3cm f/1.9 Hektor could be used with 5cm f/1.5 Xenon lens⁵⁴². It was known that Ernst Leitz, New York, also made folding hoods for 5cm f/1.5 Xenon lenses in chrome and black finishes⁵⁴².

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 lost²²³. Many 5cm f/1.5 Xenon lenses were then 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 was 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 could also be used⁷². Additionally, it could accommodate the screw-in E41 type filter⁷². Filters for both the 5cm f/1.5 Xenon and 50mm f/1.5 Summarit lenses were 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. According to Helmut Lagler, however, overall, there were 13010 lenses produced between 1935 and 1939, with serial numbers ranging from 270001 through 492000⁴³⁹. According to a different source, approximately 6,100 5cm f/1.5 Xenon lenses were produced from 1935 to 1939, with an additional 122 units manufactured between 1948 and 1952³⁶⁰.

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 humidity²⁷⁵. Four groups of 5cm f/2 Summar TROPEN lenses, over 100 pieces in total, labeled “Gruppe I, II, III, and IV,” were documented in the Leica Solms archive²⁷⁵. One author concluded that the four control groups were assigned to monitor various parameters, including resistance to fungus²⁷⁵. The 5cm f/2 Summar TROPEN lenses were dispatched primarily to tropical destinations²⁷⁵.

Between June and September 1938, 5cm f/2 Summar TROPEN 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)²⁷⁵. 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) featured a six-element design, while product 42214 (Tropen) was a seven-element model²⁷⁵. A comparison of the cross-sections revealed that the 42214 (Tropen) model included an additional element at the front of the lens²⁷⁵(optical formula B246a)³⁹⁶.

It remained unclear whether all the lenses were identical or if their glass compositions were altered²⁷⁵.

The results of this testing and evaluation are unknown, and any information gathered from this effort was likely lost to history following the introduction of the significantly improved 5cm f/2 Summitar (SOORE) in 1939²⁷⁵. In turn, 5cm f/2 Summar TROPEN lenses were to be found among the late 5cm f/2 Summar lenses shortly before the introduction of the 5cm f/2 Summitar and the only difference visible from the outside was the groove along the collapsing barrel, same as in the 5cm f/2 Summitar lenses³⁸¹.

Known Samples

Known lenses of 5cm f/2 Summar TROPEN type were:

unnumbered prototype dated circa 1937 was auctioned off at the 35th Leitz Photographica Auction
410007 was offered for sale on eBay in August of 2026.
410028 was manufactured in 1937³⁸⁵. The lens was offered but remained unsold at the 38th Leitz Photographica Auction on June 12, 2021³⁸⁵. It was offered for sale at Leica Classics Store in Vienna in August of 2026.
410047 was manufactured in 1938⁴²⁷. The lens was sold for 2800 Euros including buyer's premium at the 2nd Wetzlar Camera Auction on October 10, 2020⁴²⁷.
410077 was illustrated in Mr. Lars Netopil's "Rare Leica" book in 2014⁵⁹⁴.
410086 was manufactured in 1938³⁸¹. Lens was sold for 6600 Euros including buyer's premium at the 42nd Leitz Photographica Auction on June 9 and 10, 2023³⁸¹. Before that, it was sold for 2400 Euros including buyer's premium at the 3rd Wetzlar Camera Auction on October 9, 2021⁴²⁶.
410089 was manufactured 1938 and sold for 2000 Euros including buyer's premium at the 1st Wetzlar Camera Auction on October 5, 2019⁴²⁸.
410090 was delivered to New York in 1935³⁷⁷. The lens was offered for sale at the 46th Leitz Photographica Auction on June 27, 2025, but remained unsold³⁷⁷.
410120 dated 1937 was sold for 4560 Euros including buyer's premium at the 26th WestLicht Camera Auction on November 22, 2014³⁹⁷.
410127 was auctioned off at the 11th WestLicht Camera Auction.
410134 was auctioned off at the Lidong Camera auction in June of 2026.
410186 was featured on Fotochaton blog.
410190 dated 1937 was delivered in 1938³⁸². Lens was sold for 3600 Euros including buyer's premium at the 41st Leitz Photographica Auction on November 26, 2022³⁸².
410300 was manufactured in 1937396. The lens was sold for 3360 Euros including buyer's premium at the 27th WestLicht Camera Auction on June 13, 2015396.
410355 was delivered in 1938382. Lens was sold for 3600 Euros including buyer's premium at the 41st Leitz Photographica Auction on November 26, 2022382.
410427 dated 1938 was sold for 3000 Euros including buyer's premium at the 11th WestLicht Camera Auction on May 26, 2007⁴¹³. The lot was described as "...delivered to Schmidt, Singapore on September 3rd, 1938..."⁴¹³.
410474 was sold for 13200 Euros including buyer's premium at the 20th WestLicht Camera Auction on November 12, 2011⁴⁰⁴.

5cm f/2 Summitar

The 5cm f/2 Summitar (code-named SOORE²⁷⁵), introduced in 1939, replaced the 5cm f/2 Summar³⁶⁰. 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 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 lens²⁸⁴. At the same time, the design aimed to effectively illuminate the corners of the frame at full aperture²⁸⁴. To reduce the falloff of illumination at the edges and corners when shooting at large apertures, a large front element was incorporated into the design²⁸⁴.

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 large front element, measuring 42mm³⁶⁰, was particularly important for slides made with the high-contrast color transparency films from Kodak and Agfa, which were introduced starting in 1937²⁸⁴. And that's why the 5cm f/2 Summitar was particularly favored by users of the newly introduced Kodachrome film³⁶⁰.

Additionally, these new lenses were markedly less sensitive to environmental factors, dust, and fingerprints³⁶⁴.

A few 5cm f/2 Summitar lenses were produced in 1953, with a very limited quantity made as late as 1955²⁸⁴.

Prototype

The 50mm f/1.5 Summitar, developed during the war, never advanced beyond the prototype stage³⁶⁰. No prototype specimen was available in the Wetzlar museum, and a rumoured specimen that might have existed elsewhere was not confirmed³⁶⁰.

A prototype 5cm f/2 Summitar, labeled "Summar", wasillustrated in Mr. Lars Netopil's "Museum Leica" book in 2018⁵⁹⁶.

A prototype dual-lever bayonet mount Summitar-M was illustrated in Mr. Lars Netopil's "Rare Leica" book in 2014⁵⁹⁴.

Factory Coating

The factory coating for this lens commenced on November 9, 1945 with serial number 587601⁴⁶¹.

Variants

Variant 1 came with a European aperture scale: 2, 2.2, 3.2, 4.5, 6.3, 9, and 12.5; featured a conventional round iris made of multiple flat blades; chrome finish, uncoated³⁶⁰. The very large and uncoated front element of this variant made it particularly prone to stray light³⁶⁴. Thus, Leitz strongly recommended³⁶⁴ using the relatively large clamping screw-type folding lens hood (code: SOOPD)³⁶⁰that accompanied the lens³⁶⁴. The variant featured a plain rim to accommodate for SOOPD³⁶⁰.
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 was minimized, while light transmission and image contrast were enhanced³⁶⁴.
Variant 3 came with an international aperture scale: f2, 2.8, 4, 5.6, 8, 11, and 16 (starting from number 611000³⁶⁰, early 1946⁵⁴²)
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 SOOPD); pressure on either side of the hood released it from the lens³⁶⁰. Introduced in 1951³⁶⁰.

Unusual examples

Lens number 553384 dated 1941 described as "Summitar 2/5cm 'Aluminium Rim' - The focusing mount is made of aluminum and unfinished...Ex Theodor Kisselbach collection...is an item from the Leitz design and development department. It was internally at Leitz Wetzlar delivered to chief designer Wilhelm Albert, Oskar Barnack’s direct successor and head of the Leica design department, on January 9, 1941."³⁹⁹.

Lens number 577832 dated 1941 described as "Summitar 2/5cm Gold 'Karl Henkell'...this lens was used with Leica III Luxus no.55493, though the Leitz archive does not mention the gold plating - still it looks absolutely original made by Leitz and we are sure that it was specially done for Karl Henkell at the time, with gold plated front cap"⁴⁰¹.

Lens number 622353 dated 1946 described as "...unique Summitar with a different design of the collapsible barrel, possibly a prototype or test sample.."³⁸⁷.

Lens number 860120 dated 1951 with original Leitz engraving 'Leitz-Eigentum M'³⁹⁵.

Variations of Front Lens Rims and Lens Hoods

There were tree different variants of the front lens rims, each of which was compatible with a specific lens hood⁵⁴²:

lenses with plain front lens rim were compatible with the clamp-screw SOOPD lens hoods⁵⁴²
lenses with V-grooved rims were compatible with the clamp-screw SOOPD lens hoods⁵⁴²
lenses with flat-grooved rims were compatible with the spring-loaded gripper SOOPD lens hoods⁵⁴²

SOOPD lens hoods were made both by Ernst Leitz, Wetzlar and Ernst Leitz, New York⁵⁴².

Other Accessories

In his "Geburtstage der Leitz-Foto-Konstruktionen ab 1927" book, Wilhelm Albert dated "birthday" of the grip for single-arm right-handed use for this lens ("5 cm Summitar mit Griffschraube für Rechtshand (einarmig)") as August 12, 1957, and noted W. Mohr as designer⁵⁷³.

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, W.Haven³⁶⁰, Aeronautica Militare (e.g., 667474 dated 1948³⁸¹, 667482 dated 1948⁴⁰³), Emden (e.g., 561201 dated 1941³⁸⁶).

In 1940, 553 5cm f/2 Summitar lenses, with serial numbers ranging from 506301 through 552243, were delivered to the German military organizations³⁶⁴.

In 1941, 119 5cm f/2 Summitar lenses, with serial numbers ranging from 551053 through 562747, were delivered to the German military organizations³⁶⁴.

In 1942, 116 5cm f/2 Summitar lenses, with serial numbers ranging from 563116 through 584507, were delivered to the German military organizations³⁶⁴.

In 1943, 59 5cm f/2 Summitar lenses, with serial numbers ranging from 577975 through 586267, were delivered to the German military organizations³⁶⁴. It was known that several coated examples were delivered to the Luftwaffe in 1943²⁸⁴. 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.

Closing Remarks

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

The 5cm f/2 Summitar was eventually succeeded by the 5cm f/2 Summicron³⁶⁰. Over 170000 5cm f/2 Summitar lenses were produced between 1938 and 1955²¹⁷, with a peak production of about 28000 units in 1950³⁶⁰.

5cm f/1.5 Summarit

Pre-series and the 490XXX Series

The final batch of 5cm f/1.5 Xenon lenses was assigned serial numbers from 490001 to 492000, with production beginning in 1939⁵⁹¹. However, records indicated that only up to 491897 were actually produced⁵⁹¹. After the war, the remaining numbers from 491898 to 492000 were likely used for prototypes of the improved 5cm f/1.5 Summarit⁵⁹¹. It remained unclear whether all 102 lenses were produced, as it appeared that not all numbers were utilized by the end of the serial number range⁵⁹¹. The highest known number was 491942, suggesting that around 50 lenses may have been made⁵⁹¹.

It was known that a very small number of 5cm f/1.5 Summarit lenses had serial numbers in the 490XXX range⁵⁹¹. While some sources suggested these numbers dated back to around 1939, implying they were manufactured before the war, they were actually produced in 1949⁵⁹¹. Some researchers considered lenses in the 490XXX range to be prototypes of the 5cm f/1.5 Summarit⁵⁹¹.

Introduced in 1949³⁶⁰ with serial number 491898³⁶¹, the 5cm f/1.5 Summarit lens (code-named SOOIA) featured a seven-glass construction similar to that of the 5cm f/1.5 Xenon lens, which it replaced³⁶⁰. The screw-mount 50mm f/1.5 Summarit was in a way a coated version of the 50mm f/1.5 Xenon lens³⁶¹.

One notable lens, number 491935, with the focusing distance marked in meters, was illustrated on page 50 of Camera Review No. 75 (Leica-Book '05)⁵⁹¹. The absence of the Taylor, Taylor Hobson markings indicated that it was intended for the German domestic market⁵⁹¹.

An unnumbered prototype was illustrated on page 158 of Shinichi Nakamura's "Leica Collection" (1991) book⁶⁰². In summer of 2026, this (or a very similar lens) was believed to be part of Austrian collection.

Mass Production

The first mass-produced 5cm f/1.5 Summarit lenses consisted of 1,000 units produced in 1949, with serial numbers ranging from 740001 to 741000⁵⁹¹. There were no significant external differences between these lenses and those in the 490XXX series⁵⁹¹. However, the lenses in the 490XXX series were slightly smaller and lighter, weighing only 280g⁵⁹¹.

The back of the helicoid lever on lens number 491935 featured a "C" marking, indicating that the actual focal length of this lens was 50.9 mm⁵⁹¹. Most other 5cm f/1.5 Summarit lenses bore a "2" marking, corresponding to a focal length of 51.1 mm⁵⁹¹. This suggested that the design standards between these lenses differed slightly, rather than it being a tolerance issue⁵⁹¹.

The design of 5cm f/1.5 Summarit was 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 Hobson³⁶⁰. Lenses exported to the United States had patent number details engraved on the lens mount by the Taylor company³⁶⁰.

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 down³⁵⁸. It replaced the previous 5cm Xenon f/1.5 lens and featured a seven-element optical design that provided outstanding color correction and contrast³⁵⁸. 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 photography³⁵⁸. 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 of the screwmount 5cm Summarit f/1.5 was made of brass and the lens weighted 310 gram⁵⁹¹.

Earlier 5cm Summarit f/1.5 lenses featured a fixed aperture scale on the lens barrel, while later models changed this design by fixing the aperture indicators and allowing the aperture scale to rotate instead⁵⁹¹.

Variants

Variant 1 had a screw mount; no infrared marking³⁶⁰.
Variant 2 had a reversed iris scale (marked right to left); featured a different style of engraving³⁶⁰.
Variant 3 was same as variant 2, but engraved with "Ernst Leitz Canada Ltd."³⁶⁰. Small screw mount and bayonet mount Canadian batches recorded include serial numbers 1053XXX, 1246XXX, 1418XXX ²²³, 1419XXX (author's note) and 1420XXX (author's note). 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 works¹⁶⁸. These lenses could be easily identified by the presence of an optical unit marked "Canada," while the focusing mount is engraved with "Germany."²²³. This variant was very rare³⁶⁰. 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 was a unique black-painted lens number 1120021³⁸⁵. This lens was part of an outfit that was made as a final test before the Swedish Army version of Leica IIIg was issued³⁸⁵.

Lens Hoods

XOONS was the lens hood for 50mm f/1.5 Summarit⁵⁴². There were few variations:

Wetzlar made prototype lens hood with bayonet fitting³⁶⁴. A report from October 17, 1949, confirmed that that Werner Mohr developed a foldable lens hood for the 5cm f/1.5 Summarit in 1949³⁶⁴. This prototype non-folding octagonal hood featured two dimples for bayonet attachment to the lens's notched ring, along with a cut-out to avoid obstructing the camera's rangefinder windows²²³. This design also required precise alignment with the lens for proper function, which led Leitz to favour the XOONS clamping hood while retaining the octagonal shape²²³.
New York made prototype lens hood with bayonet fitting⁵⁴². According to James L. Lager, in October of 1950, Ernst Leitz, New York, price list featured a collapsible lens hood for the 5cm f/1.5 Summarit⁵⁴². This type of lens hood never made it to the commercial market⁵⁴². A similar folding hood was preserved in the Leitz Museum²²³and illustrated on page 51 of James L. Lager's "Leica: An Illustrated History - Volume 2 - Lenses - Signed Deluxe Limited Edition" book⁵⁴².
With bayonet fitting⁵⁴². Early models of 5cm f/1.5 Summarit lenses featured a bayonet mount for lens hoods and filters³⁶⁰. Few bayonet fitting lens hoods were sold with early lenses with serial numbers 491XXX, making those lens hoods rare²²³.
With screw fitting⁵⁴². Later lenses were equipped with a screw-mount filter thread³⁶⁰ that would accept clamp-screw-style XOONS lens hoods⁵⁴².

Prototypes

Several known prototypes:

screw mount prototype number 0000000 was illustrated in Mr. Lars Netopil's "Museum Leica" book in 2018⁵⁹⁶.
screw mount prototype number 0000007, dated 1954, was known and was produced in June of 1954 (formula B284b)⁴⁰².
screw mount prototype number 0000008, dated 1954, was known and was produced in June of 1954 (formula B284b)⁴⁰².

Lenses 1526985 and 1526987

These two lenses were illustrated on page 51 of Camera Review No. 75 (Leica-Book '05)⁵⁹¹.

1526985 was a screwmount 5cm f/1.5 Summarit lens with distance markings in feet that had a beauty ring drastically different from commercial versions⁵⁹¹. It was engraved "Summarit f=5cm 1:1.5 Nr. 1526985"⁵⁹¹.

1526987 was a bayonet mount 5cm f/1.5 Summarit lens with a beauty ring drastically different from commercial versions⁵⁹¹. It was engraved "Summarit f=5cm 1:1.5 Nr. 1526987 Midland 1234567"⁵⁹¹. The number "1234567" served as an identification number that Leitz Canada used for prototype or internal lenses⁵⁹¹. While this number was typically not displayed alongside the regular serial number, this lens was an exception, making it a rare example with dual numbering⁵⁹¹.

The serial numbers in the 152XXXX corresponded to the final production run of the 5cm f/1.5 Summarit series, indicating 1526985 and 1526987 were no longer prototypes⁵⁹¹. However, the coating on both lenses differed from that of standard products, suggesting they were likely test pieces for the coating process⁵⁹¹.

Closing Remarks

Production of all 50mm f/1.5 Summarit lenses ceased after the introduction of the new 50mm f/1.4 Summilux in 1959²²³. 1960 marked the last year when 50mm f/1.5 Summarit was catalogued⁵⁴².

5cm f/2 Summitar*

The 5cm f/2 Summitar* prototype lens, developed in September 1950³⁶¹, served as the foundation for the 5cm f/2 Summicron lens³⁶⁰.

This prototype was similar in design to the standard 5cm f/2 Summitar, but was crafted using finer rare earth glasses, such as Lanthanum³⁶⁰. The 5cm f/2 Summitar* lens is fitted with a 5cm f/2 Summitar mount but differs from 5cm f/2 Summitar by closing the iris at f/22, instead of f/12.5 or f/16³⁶⁰. However, tests indicated that this additional stop was counterproductive, resulting in its later removal in the production model of the 5cm f/2 Summicron¹³². All 5cm f/2 Summitar* lenses were engraved with only a meter distance scale¹³². 5cm f/2 Summitar* lenses can be easily identified by its shorter length when extended—37 mm compared to 43 mm for the original 5cm f/2 Summitar¹³².

In 1952, several 5cm f/2 Summitar* lenses were given to notable photographers and members of the Leitz sales staff for field testing and evaluation¹³². These prototypes were designated with an asterisk to indicate their prototype status, a practice that had since been adopted as standard procedure at Leitz¹³². Recipients of these lenses provided feedback back to the design laboratory and typically returned the lenses for further factory testing¹³². This process often resulted in the teardown and destruction of the lenses, contributing to the extreme scarcity of the 5cm f/2 Summitar* lens¹³². Surviving lenses were later awarded to select employees and ultimately found their way into the collector's market¹³².

A Geiger counter can be used to verify the authenticity of the 5cm f/2 Summitar* Prototype lens¹³².

In his "Über das Summitar* f 5 cm 1:2" article, published on pages 89-91 of the "10 Jahre Leica HISTORICA: Beiträge zur Geschichte der LEICA", Ilf Richter compared 5cm f/2 Summitar* lens to early 5cm f/2 Collapsible Summicron number 1478651⁵⁹⁵.

Known Examples

According to records from Wetzlar, a total of 88 5cm f/2 Summitar* lenses were produced and numbered 812242 - 812329³⁹⁹. Among them:

Lens number 812242 was auctioned off at the 46th Leitz Photographica Auction³⁷⁷.
Lens number 812245 was illustrated in Mr. Lars Netopil's "Rare Leica" book in 2014⁵⁹⁴.
Lens number 812246 was illustrated in Mr. Lars Netopil's "Rare Leica" book in 2014⁵⁹⁴.
Lens number 812252 was auctioned off at the 13th WestLicht Photographica Auction⁴¹¹.
Lens number 812265 was auctioned off at the 47th Leitz Photographica Auction⁵³³. Before that, it was auctioned off at the 43rd Leitz Photographica Auction³⁸⁰.
Lens number 812270 was auctioned off at the Christie's Auction on June 15, 2004.
Lens number 812274 was auctioned off at the 34th Leitz Photographica Auction³⁸⁹.
Lens number 812275 was received by the works manager at Leitz, Henri Dumur¹³², according to Ulf Richter⁵⁹⁵.
Lens number 812276 was illustrated on page 46 of James L. Lager's "Leica: An Illustrated History - Volume 2 - Lenses - Signed Deluxe Limited Edition" book⁵⁴². It was illustrated in Mr. Lars Netopil's "Museum Leica" book in 2018⁵⁹⁶.
Lens number 812279 was auctioned off at the 24 WestLicht Photographica Auction⁴⁰⁰.
Lens number 812285 was auctioned off at the Christie's Auction on March 11, 2003.
Lens number 812290 was part of first delivery (No. 73332) and was received by export manager Becker on March 3, 1952¹³².
Lens number 812292 was auctioned off at the 38th Leitz Photographica Auction³⁸⁵.
Lens number 812294 was auctioned off at the 24 WestLicht Photographica Auction⁴⁰⁰.
Lens number 812296 was auctioned off at the "100 years of Leica Camera" Leitz Photographica Auction³⁹⁹. Before that, it was auctioned off at the 14th WestLicht Photographica Auction⁴¹⁰.
Lens number 812297 was auctioned off at the "100 years of Leica Camera" Leitz Photographica Auction³⁹⁹. This particular lens was 1 of only 6 lenses that were Summitar* with a central-shutter³⁹⁹, referred to as 5cm f/2 Compur Summitar*. The lens was not only forerunner for 5cm f/2 Summicron but also a prototype of the later 5cm f/2 Compur Summicron³⁹⁹.
Lens number 812298 was auctioned off at the 32nd WestLicht Photographica Auction³⁹¹. The lot description read: "according to the previous owner it was directly acquired from Mr. Keller (former employee at Leitz scientific division)"³⁹¹. Before that, it was auctioned off at the 27 WestLicht Photographica Auction³⁹⁶.
Lens number 812308 was auctioned off at the 16 WestLicht Photographica Auction⁴⁰⁸.
Lens number 812309 was auctioned off at the 45th Leitz Photographica Auction³⁷⁸. This lens was delivered to the Austrian photographer and 'ski Pope' Stefan Kruckenhauser³⁷⁸.
Lens number 812321 was auctioned off at the 17 WestLicht Photographica Auction⁴⁰⁷.
Lens number 812322 was auctioned off at the 33rd WestLicht Photographica Auction³⁹⁰.
Lens number 812327 was auctioned off at the 10th WestLicht Photographica Auction⁴¹⁴. This particular lens was 1 of only 6 lenses that were Summitar* with a central-shutter³⁹⁹, referred to as 5cm f/2 Compur Summitar*. The lens was not only forerunner for 5cm f/2 Summicron but also a prototype of the later 5cm f/2 Compur Summicron³⁹⁹.
Lens number 812352 was expected to be auctioned off at the 8th Wetzlar Camera Auctions on October 10, 2026⁵⁹⁷.

5cm f/2 Compur Summitar*

In 1950⁵²⁴-1951, Leitz New York informed Wetzlar of a special request from a valued customer¹³⁴. 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 speed¹³⁴. He requested that a way be developed to achieve electronic flash synchronization at higher shutter speeds¹³⁴. Since the synchronization speed was determined by the design of the basic black dial focal plane shutter, Leitz decided to approach the problem differently¹³⁴. Leitz collaborated with Alfred Gauthier from Calmbach (and Leitz designer Erwin Neurath from the research staff¹³⁴⁾to develop a prototype of the non-retractable Summitar 5cm f/2 lens equipped with a Prontor central shutter⁵²⁴. A leaf shutter could provide X-sync at speeds of up to 1/500 second¹³⁴. Leitz designer Erwin Neurath succeeded, leading to the creation of the exquisitely rare 5cm f/2 Compur Summitar*¹³⁴.

It is worth noting that both the 5cm f/2 Summitar* and 5cm f/2 Compur Summicron lenses were considered rare finds among Leica lenses from the 1950s³⁹⁹. The combination of these two lenses was particularly unusual, as only six units of the Summitar* were produced with central-shutter lenses - these were referred to as 5cm f/2 Compur Summitar*³⁹⁹. These lenses not only preceded the 5cm f/2 Summicron, but also served as prototypes for the later 5cm f/2 Compur Summicron³⁹⁹. 5cm f/2 Compur Summitar* was extremely difficult to find³⁹⁹.

It was presumed that all six units of 5cm f/2 Compur Summitar* were in the serial number range of 812279³⁹⁹ - 812327¹³⁴. The source of the quantity of 6 was (Willi?) Thurau, who mentioned them in VIDOM 6⁵⁹⁵. These lenses differed from the usual 5cm f/2 Summitar* Prototype in that they stop down to f/16 instead of f/22¹³⁴. Among known 5cm f/2 Compur Summitar* lenses were:

Lens number 812297 was illustrated on the Page 35 of the "Classic Camera" magazine Issue 1 from February 1997. Later, it was auctioned off at the "100 years of Leica Camera" Leitz Photographica Auction³⁹⁹and at the OstLicht Auctions on June 5, 2024.
Lens number 812301 was referenced on the Page 34 of the "Classic Camera" magazine Issue 1 from February 1997 as "In Van Hasbroeck's book on Leicas it is photographed with the number 812 301".
Lens number 812327 was auctioned off at the 10th WestLicht Photographica Auction⁴¹⁴. This lens was illustrated on page 123e of James L. Lager's "Leica: An Illustrated History - Volume 2 - Lenses - Signed Deluxe Limited Edition" book⁵⁴².

None of the original six 5cm f/2 Compur Summitar* lenses were sold to the public; after testing, they were returned to the model shop¹³⁴. They were later acquired by privileged Leitz employees¹³⁴.

5cm f/2 Collapsible Summicron

The 5cm f/2 Summicron (both collapsible variant of 1953 (SOOIC⁵⁴²) and rigid variant of 1960 (SOSTA⁵⁴²)) was based on a prototype 5cm f/2 Summitar* lens, which was designed in 1950³⁶⁰.

The 5cm f/2 Collapsible Summicron (SOOIC⁵⁴²) was introduced in 1953⁵⁴²with serial number 920001⁴³⁹.

It incorporated rare earth elements and was 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.

The 5cm f/2 Collapsible Summicron featured a non-rotating collapsible mount, a click-stop iris (from f2 to f16), and an E39 filter mount³⁶⁰. Early models had an infrared marking on the focusing scale³⁶⁰.

From 1953 to 1961⁵⁴², over 60000 5cm f/2 Collapsible Summicron lenses were manufactured³⁶⁰.

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 50mm f/2.8 Elmarit never progressed beyond the prototype stage³⁶¹. The said prototype 5cm f/2.8 lens (possibly 50mm f/2.8 Elmarit³⁶¹) with a rigid mount (no. 000754) had a similar design to that of the 5cm f/2 Rigid Summicron³⁶⁰.

"Summicron" had been a registered trademark of Leica Camera AG since January 23, 1952⁵³⁴.

A prototype with screw mount, with aperture stopping down to f/32 and FM149 engraved on the beauty ring, was illustrated in Mr. Lars Netopil's "Museum Leica" book in 2018⁵⁹⁶.

Some of the known lenses of the 920XXX series included:

920003 - M-Mount prototype⁵⁸⁸
920050 - screw-mount, illustrated in Camera Review No. 71 (Leica-Book '04)⁵⁸⁸

5cm f/2 Compur Summicron

Patent

A patent outlining the two-shutter system for flash synchronization at zero delay was applied for in 1953⁵²⁴ and granted in 1955¹³⁴. This patent certificate for the Compur-Summicron, numbered 894650 and issued in 1953, listed Leitz engineers Adam Wagner and Werner Willi Wiessner, along with Gauthier employee Albert Nübel, as the inventors⁵²⁴. Unusually for a patent document, this one featured detailed illustrations with numerous labeled sections that not only described the concept in depth but also demonstrated how it operated⁵²⁴. The intricate design allowed for the complex operating sequence of the lens and the connection between the camera and central shutter through a release lever, all achieved in a compact and elegant solution⁵²⁴. Undoubtedly, the Compur-Summicron stood out as one of the company’s significant engineering achievements⁵²⁴. The release lever unit alone was a testament to fine mechanics, its modest exterior hiding a complex arrangement of small latches, locking levers, axles, compression springs, and inclined surfaces⁵²⁴. Specialized machinery was required to shape the curves and arches of the release lever, which was designed to operate the release arm of the Compur-Summicron⁵²⁴.

Special Order

However, the 5cm f/2 Compur Summicron remained on hold until its release in 1954 by the company's American subsidiary, Ernst Leitz Inc⁵²⁴, who began producing it on a special order basis¹³⁴. This lens, available only from 1954 to 1956, facilitated flash photography at shutter speeds of 1/100 and 1/200 of a second⁵²⁴. While many authors assumed that the 5cm f/2 Compur Summicron was a prototype, Dr. Bahman Bawendi asserted that the officially assigned serial numbers suggested otherwise⁵²⁴. Additionally, according to Dr. Bawendi, a two-page instruction manual published by Leitz Inc.⁵²⁴ issued in 1955¹³⁴ clearly indicated that the lens was intended for the market, at least within the US⁵²⁴. Yet, no catalog code was assigned¹³⁴.

Construction Details of 5cm f/2 Compur Summicron

Minor changes were made to the leaf shutter of 5cm f/2 Compur Summitar*, as evidenced by the reversal of the speed sequence engraved on top of the mount¹³⁴. The speed lever was slightly modified to prevent the entry of dust and other foreign matter through the selector slot¹³⁴. There appear to be two slightly different release arms: one designed for the Leica IIIf model and the other, which is slightly taller, meant for the Leica IIIg model available after 1957¹³⁴. A special cammed shutter release arm was required to use the lens at its synchronization speeds of 1/100 and 1/200 of a second¹³⁴.

Use of 5cm f/2 Compur Summicron with Leica IIIf

The Leica IIIf 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 shutter¹³⁴. Continued pressure on the release opened the camera shutter, triggered the leaf shutter, and ultimately allowed the camera's shutter to close¹³⁴. Releasing the pressure on the lever permitted the leaf shutter to open again¹³⁴. A simple adjustment was necessary to calibrate the mechanism for each individual camera¹³⁴. Here is what the adjustment process looked like: First, the locking screw on the release lever unit was slightly loosened⁵²⁴. This allowed the photographer to properly time the shutter release button by rotating the adjustment screw half a turn⁵²⁴. Once the correct timing was achieved, the locking screw was securely tightened again⁵²⁴. Dr. Bahman Bawendi provided illustrations on page 63 of Leica Fotografie International magazine, March 2016⁵²⁴.

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 synchronization¹³⁴.

Quantities of 5cm f/2 Compur Summicron

Determining the exact number of 5cm f/2 Compur Summicron units manufactured was quite challenging⁵²⁴. Some authors thought that due to low demand, only a total of 58 units were delivered before production ceased in 1955¹³⁴. Dr. Bahman Bawendi did not agree with this number⁵²⁴. According to the company's official sales ledger, 26 5cm f/2 Compur Summicron lenses were shipped to retailers, and three of these were later returned, thus only 23 units of the 5cm f/2 Compur Summicron were sold⁵²⁴. Evidence showed that a total of 150 lenses were actually produced⁵²⁴. These lenses came from three separate production runs of 50 units each⁵²⁴, with serial numbers ranging from 1152101 to 1152150, 1155751 to 1155800, and 1168601 to 1168650¹³⁴.

In 1964, 73 out of the 92 lenses that had been left at the production plant were sold to Leitz employees⁵²⁴. Several years later, the remaining 19 units were also sold in-house⁵²⁴. Most of these lenses were no longer in their original condition, as many owners had used the 5cm f/2 Compur Summicron as a conventional lens⁵²⁴. This led to the removal of both the connection pin for attaching the flash unit and the release arm of the Compur central shutter, which were often discarded⁵²⁴. By today, only about one-third of the 5cm f/2 Compur Summicron lenses known are still complete and in their original condition⁵²⁴.

Known Examples

Known 5cm f/2 Compur Summicron lenses were:

Lens number 1095051 was auctioned off on June 5, 2024 at the OstLicht Auctions, and was described as "Rare Leica IIIf Betriebskamera no.336 with unique prototype Compur-Summicron 2/5cm lens no. 1095051 in aluminium mount. All outer parts of this lens are of a different design than the 150 pieces from the official production. The lens comes with a prototype release-arm, which is also different in design. The lens was built one year before the production of the Compur Summicron started from nos. 1152xxx. This lens is published by Ottmar Michaely in Leica Historica e.V. VIDOM magazine Nr. 95 (2008), p.36. Lens and camera are in almost perfect condition.".
Lens number 1095052, dated 1952, was illustrated on the Page 34 of the "Classic Camera" magazine Issue 1 from February 1997. The lens was described as "the only one I have seen without a manually opening shutter. This may appear as an oversight, by may also have been the prelude to a Leica without a film plane shutter. Surface finish is also different". This lens was illustrated on the back cover of 1995 Camera Review No. 32 (Leica-Book '95) magazine, on a Leica IIIf Red Dial number Betriebsk. Nr.362.
Lens number 1126654, dated 1954, was auctioned off at the Christie's on June 17, 1999, and later at at the 24 WestLicht Photographica Auction.
Lens number 1152104, dated 1954, was auctioned off at the 44 Leitz Photographica Auction.
Lens number 1152106, dated 1954, was auctioned off at the 26 WestLicht Photographica Auction.
Lens number 1152107, dated 1954, was illustrated on the Page 36 of the "Classic Camera" magazine Issue 1 from February 1997.
Lens number 1152126 was auctioned off on March 26, 2022 at the Auction Team Breker
Lens number 1152134 was illustrated in Mr. Lars Netopil's "Museum Leica" book in 2018⁵⁹⁶.
Lens number 1155711 was expected to be auctioned off at the 8th Wetzlar Camera Auctions on October 10, 2026⁵⁹⁷.
Lens number 1155712 without infinity lock was illustrated on the Page 34 of the "Classic Camera" magazine Issue 1 from February 1997.
Lens number 1155714 was auctioned off at the Bonhams on December 2, 2020
Lens number 1155751, dated 1954, was auctioned off at the 5 WestLicht Photographica Auction.
Lens number 1155757, dated 1954, was auctioned off at the 29 WestLicht Photographica Auction.
Lens number 1155769 was auctioned off at the 20 WestLicht Photographica Auction. This lens was featured on page 44 of James L. Lager's "Leica: An Illustrated History - Volume 2 - Lenses - Signed Deluxe Limited Edition" book⁵⁴². It was illustrated on page 85 of Shinichi Nakamura's "Everything About the Barnack-type Leica" (1992) book.
Lens number 1155771, dated 1954, was auctioned off at the 23 WestLicht Photographica Auction.
Lens number 1155777, dated 1954, was auctioned off at the 25 WestLicht Photographica Auction.
Lens number 1155782, dated 1954, was auctioned off at the 14 WestLicht Photographica Auction.
Lens number 1155784, dated 1954, was auctioned off at the 38 Leitz Photographica Auction.
Lens number 1155788, dated 1954, was auctioned off at the 14 WestLicht Photographica Auction. This lens was illustrated on the Page 34 of the "Classic Camera" magazine Issue 1 from February 1997.
Lens number 1155789, dated 1954, was auctioned off at the 8 WestLicht Photographica Auction.
Lens number 1155792 was illustrated in Mr. Lars Netopil's "Rare Leica" book in 2014⁵⁹⁴.
Lens number 1168607, dated 1954, was auctioned off at the 34 Leitz Photographica Auction.
Lens number 1168608, dated circa 1955, was auctioned off at the 19 WestLicht Photographica Auction.
Lens number 1168610 was offered on November 15, 2025 at an American auction.
Lens number 1168612, dated 1955, was auctioned off at the 24 WestLicht Photographica Auction.
Lens number 1168613, dated 1954, was auctioned off at the 100 years of Leica Camera Leitz Photographica Auction.
Lens number 1168614, dated 1954, was auctioned off at the 46 Leitz Photographica Auction.
Lens number 1168618 with bayonet M-mount was illustrated on the Page 34 of the "Classic Camera" magazine Issue 1 from February 1997.
Lens number 1168619, dated 1954, was auctioned off at the 42 and 40 Leitz Photographica Auction.
Lens number 1168620 was auctioned off at the Christie's on June 11, 2002.
Lens number 1168644, dated circa 1955, was auctioned off at the 15 WestLicht Photographica Auction.
Lens number 1168645, dated 1954, was auctioned off at the 37 Leitz Photographica Auction.
Lens number 1168647, dated 1954, was auctioned off at the 33 Leitz Photographica Auction.

50mm f/2.8 Elmar

Prototypes

In his "Geburtstage der Leitz-Foto-Konstruktionen ab 1927" book, Wilhelm Albert dated the "birthday" of 5cm f/2.8 Elmar lens ("Objektive Elmar 5 cm 1:2,8") as November 3, 1954, and noted Werner Schlapp as designer⁵⁷³. Judging by illustrations on the page 154, one could assume that Wilhelm Albert meant both screw mount and bayonet mount versions were "born" that day⁵⁷³. The following items were illustrated the afore-mentioned photograph (Nr. 6595)⁵⁷³:

1. lens head ("abschr. Kopf") of the lens⁵⁷³

2. prototype bayonet mount lens with graduated guide ("mit Gradführ. (Summicron Schnecke)") from 5cm f/2 Collapsible Summicron (SOOIC)⁵⁷³

3. bayonet mount lens⁵⁷³

4. screw mount lens without graduated guide ("ohne Gradführ.")⁵⁷³

5. prototype screw mount lens with graduated guide and outer diameter of 36mm ("m. Gradführ. 36 Auben ∅")⁵⁷³. This A-36 version of 5cm f/2.8 Elmar lens that was also illustrated on page 59 of James L. Lager's "Leica: An Illustrated History - Volume 2 - Lenses - Signed Deluxe Limited Edition" book⁵⁴². The photograph was credited to "Hooper photo"⁵⁴². The same prototype could be found on page 41 of "Leica. Tsushin No. 6: Mechanism and Prototype" magazine in 2002⁵⁷⁰. It was part of Leica Museum at Solms in 2002⁵⁷⁰. This one had a serial number filled in black, making it very hard to identify from the low resolution images.

Another 5cm f/2.8 Elmar Prototype lens in A36 mount, numbered 0000030, was illustrated in Mr. Lars Netopil's "Rare Leica" book in 2014⁵⁹⁴.

Another 5cm f/2.8 Elmar Prototype lens in A36 mount, numbered 0000069, was illustrated in Mr. Lars Netopil's "Rare Leica" book in 2014⁵⁹⁴.

Serial Production

The 50mm f/2.8 Elmar lens was introduced in March 1957⁴⁶⁰ and was a redesigned version of the earlier Elmar 3.5/50 mm³⁶¹. At the time of introduction, only screw mount version of 50mm f/2.8 Elmar was made available⁴⁶⁰.

The lens had four elements⁵⁴².

It incorporated new Lanthanum glass, which was also used in the 5cm f/2 Summicron lens³⁶¹. Although the Leitz designers aimed to improve the lens with this new material, the overall progress was modest³⁶¹. 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 minimum focusing distance was 100cm³⁶¹. The lens weighs 220 grams and had filter size E39³⁶¹. There were many small changes in engravings and design of the focusing collar³⁶¹. The outside diameter of the screw mount version was 42mm and thus it was compatible with filters for the 5cm f/2 Summicron⁴⁶⁰.

Code Names

The screw mount 50mm f/2.8 Elmar:

with meter scale had catalog number 11512 and was code-named ELMOO³⁶¹
with feet scale had catalog number 11012 and was code-named ELMOO³⁶¹

Lens Hoods

The available lens hoods for this lens were:

ITOOY⁵⁴²
IROOA⁵⁴²
12585⁵⁴²
and a lens hood engraved "Elmar 5cm" on it's chrome finished part that was illustrated on page 60 of James L. Lager's "Leica: An Illustrated History - Volume 2 - Lenses - Signed Deluxe Limited Edition" book⁵⁴². The photograph was credited to "Hooper photo"⁵⁴².

Auxiliary Close-up Lens

An auxiliary close-up lens code-named ADVOO was available for this lens⁵⁴².

Closing Remarks

The screw mount lens was listed in the catalogue from 1957-1962³⁶¹. The serial numbers ranged from 1402001 through 2503100 for screw mount and bayonet mount versions³⁶¹.

5cm f/2 Rigid Summicron

The 5cm f/2 Summicron (both collapsible variant of 1953 (SOOIC⁵⁴²) and rigid variant of 1960 (SOSTA⁵⁴²)) was based on a prototype 5cm f/2 Summitar* lens, which was designed in 1950³⁶⁰. Another prototype, number 0000356, dated 1959, was known and auctioned off as "Summicron 2/50mm Rigid prototype - an interesting prototype of a screw-mount Summicron with focusing mount similar in design to the Summarit, optical formula B666..."³⁸⁵.

The 5cm f/2 Rigid Summicron (code-named SOSTA⁵⁴²) for screw mount cameras was introduced in 1960¹³⁸.

It was released during the phase-out of the screw mount rangefinder Leica cameras by Leitz, resulting in limited production that lasted only four years, with the last units delivered in 1963¹³⁸. Factory records indicated that a total of 1160 units were produced, making it one of the rarest of the Leitz screwmount lenses¹³⁸.

Just like the screw mount 5cm f/2 Collapsible Summicron (SOOIC), the screw mount 5cm f/2 Rigid Summicron (SOSTA) was also a seven element design⁵⁴².The lens design incorporated special high refractive index glasses infused with trace amounts of rare earth elements and enhanced with special lens coatings¹³⁸. Slight changes were made in the shape of the optical components⁵⁴². This was suggested by the accompanying cross sections⁵⁴². The 5cm f/2 Rigid Summicron (SOSTA) cross sectional diagram was published in 1962 in an Ernst Leitz, Wetzlar leaflet as a reprint of articles originally appearing in Leica Fotografie⁵⁴². The screw mount 5cm f/2 Rigid Summicron (SOSTA) optical design was equivalent to the bayonet mount 50mm f/2 Rigid Summicron (SOOIC-MS / 11118) and the bayonet mount 50mm f/2 Rigid Summicron Dual Range (SOOIC-MN / 11318) lenses⁵⁴².

The minimum focusing distance was 1 meter, and the lens featured diaphragm click stops up to f/16¹³⁸. The serial number on the 5cm f/2 Rigid Summicron lens head was usually also engraved on the inside of the lens mount⁵⁴².

Original factory-produced screw mount 5cm f/2 Rigid Summicron (SOSTA) lenses were typically numbered between 1700000 and 1900000⁵⁴². It was important to note that screw mount 5cm f/2 Rigid Summicron (SOSTA) lenses with serial numbers outside this range could have still been original issues, possibly produced to accommodate special requests⁵⁴². Reported serial numbers included small batches in the ranges of 1570XXX, 1599XXX, 1704XXX, 1706XXX, 1762XXX, 1763XXX, 1885XXX, and 2181XXX¹³⁸. Units with serial numbers above 1706XXX featured an infrared focusing index¹³⁸. The low and high numbers in this range were of questionable authenticity as they fell outside the accepted manufacturing timeframe¹³⁸. Unfortunately, the collectible value of this rare lens led to a proliferation of counterfeits¹³⁸.

Conversions

In the late 1960s to early 1970s, Leitz sold screw thread focusing mounts from their repair parts inventory⁵⁴². An owner of a bayonet mount 5cm f/2 Rigid Summicron lens (either SOSIC or SOMNI) could remove the lens head and install it into the screw thread mount, thus effectively creating screw mount 5cm f/2 Rigid Summicron lens (SOSTA)⁵⁴². This transfer could have been 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 could be easily be unscrewed from a bayonet mount and transferred to the screw mount¹³⁸. The switched lens head would function well, provided care was taken to ensure the new mount matched the appropriate focal length group of the optical head¹³⁸. Unfortunately, many conversions were performed by unscrupulous individuals for monetary gain without regard for focusing accuracy¹³⁸.

Accessories

Accessories for the 5cm f/2 Rigid Summicron lens included:

4 different kinds of lens hoods:
- IROOA⁵⁴²:
  - early version (engraved "Summaron 3.5cm <new line> Summicron 5cm" on chrome section)⁵⁴²
  - late version (engraved "1:2/50 1:2.8/50 1:3.5/50 IROOA 1:2/35 1:2.8/35 1:3.5/35" on chrome section)⁵⁴²
- collapsible SOOFM (engraved "Summicron <new line> E. Leitz Wetzlar <new line> Germany" on the rear)⁵⁴²
- 12585 in black finish, engraved "1:2/50 1:2.8/50 1:3.5/50 12585 1:2/35 1:2.8/35 1:3.5/35"⁵⁴²
- ITDOO (engraved "Summaron 3.5cm <new line> Summicron 5cm" on black section and "Ernst Leitz GmbH Wetzlar" on chrome section)⁵⁴²
- 12571J (engraved "1:2/50 1:2.8/50 1:3.5/50 12571J 1:2/35 1:2.8/35 1:3.5/35" on chrome section)⁵⁴²
a near-focus attachment compatible with the M series (code SOMKY)¹³⁸
However, the close-up device for the Leica 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
iris control ring (VTROO) for use with the Focuslide¹³⁸
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)¹³⁸
All E-39 filters can be used with this lens¹³⁸

50mm f/1.4 Summilux

Prototypes

Known prototypes were:

Prototype lens number 0000214 (engraved "Summarit", but the body resembling "Summilux") was illustrated on page 96 of the "10 Jahre Leica HISTORICA: Beiträge zur Geschichte der LEICA" book in 1985⁵⁹⁵.
screw mount prototype number 0000395 (described as "Summarit", but the body resembling "Summilux") was illustrated in Mr. Lars Netopil's "Museum Leica" book in 2018⁵⁹⁶.
Prototype lens number 0000505 was illustrated in Mr. Lars Netopil's "Rare Leica" book in 2014⁵⁹⁴.

Pre-series

One source claimed the first batch of production of 50mm f/1.4 Summilux lens (SOWGE⁸²)/11014³⁶¹), including lenses with Summarit or Summilux engravings, started with no.1546001 in circa 1957⁵³³.

It was known that some prototype 50mm f/1.4 Summilux lenses were engraved "50 / 1.4 Summarit"²²³.

Among pre-series lenses:

Prototype lens number 1546020 was illustrated in Mr. Lars Netopil's "Rare Leica" book in 2014⁵⁹⁴.
Lens number 1546031 dated circa 1957, featured "LEITZ WETZLAR 1546031 SUMMILUX 1:1.4/50" engraving⁵³³. Typical for these pre-series, the numbers on the aperture scale were engraved bigger⁵³³. Another interesting aspect was that this lens had '1.4' engraved on the depth of field scale⁵³³.
Lens number 1546038, dated 1957, that was sold for 4320 Euros including buyer's premium at the 14th WestLicht Photographica Auction on November 30, 2008, with the following description: "extremely rare prototype of the later Summilux in screw mount, in 100% original mint condition with perfect clean lenses, keeper"⁴⁰⁵.
Lens number 1644041, dated 1958, featured unusual reverse knurl focusing ring style³⁸³.

Official production

The 50mm f/1.4 Summilux lens (SOWGE⁸²) was introduced in 1959 with serial number 1640601⁴³⁹. The lens entered the marked in early 1960⁵⁴².

"Summilux" had been a registered trademark of Leica Camera AG since February 6, 1959⁵³⁴.

This was an ultra-fast seven-element lens that replaced the 5cm f/1.5 Summarit³⁶⁰. In terms of optical design, it was variation of the 5cm f/1.5 Summarit lens and incorporated Lanthanum glass, which reduces flare at large apertures³⁶⁰. The lens featured chrome finish³⁶⁰. The 50mm f/1.4 Summilux lens featured a non-rotating mount and a click-stop iris mechanism³⁶⁰.

James L. Lager reported that at about the same time (1962-1963) the bayonet mount 50mm f/1.4 Summilux lens (SOOME) underwent recomputation (although the number of elements remained the same³⁶⁰) at serial number 1844001⁵⁴². The result of this recomputation was better performance⁵⁴². According to James L. Lager, the specialists wondered whether the screw mount 50mm f/1.4 Summilux lens (SOWGE⁸²) also underwent these changes⁵⁴². But they do exist, and among them⁵⁴²:

Lens number 1845073 dated 1961³⁸⁸.
Lens number 1884225 dated 1961³⁹².
Lens number 1845401 dated 1961⁴¹².
Lens number 2072499, dated 1964, that was auctioned off on 25th WestLicht Photographica Auction and described as "one of only five known SOWGE with new formula, made by special order in 1964"³⁹⁸.
Lens number 2198497 identified by James L. Lager in his "Leica: An Illustrated History - Volume 2 - Lenses - Signed Deluxe Limited Edition" book⁵⁴². The lens bore serial number from 1966 and undoubtedly was result of a special order received long after production of screw mount 50mm f/1.4 Summilux lens was ceased⁵⁴².
Lens number 2198504, dated 1966, that was auctioned off on 38th Leitz Photographica Auction and described as "with unusually late serial number, one of only four known SOWGE with the new formula, made to special order in 1966, this is for sure one of the last Summilux SOWGE lenses that left the factory"³⁸⁵.
Lens number 2220286 identified by James L. Lager in his "Leica: An Illustrated History - Volume 2 - Lenses - Signed Deluxe Limited Edition" book⁵⁴². The photograph of the lens on the page 62 of that book was credited to "J. V Walsh"⁵⁴². The lens bore serial number from 1966 and undoubtedly was result of a special order received long after production of screw mount 50mm f/1.4 Summilux lens was ceased⁵⁴².

Lens Hood

The XOOIM was the lens hood for this lens⁵⁴².

Closing Remarks

The screw mount 50mm f/1.4 Summilux lens remained in the catalog until 1962 and was listed in Ernst Leitz, New York availability sheets as late as 1963⁵⁴². The screw mount 50mm f/1.4 Summilux lenses were considered rare due to their limited production run of only 548 copies, according to Dennis Laney's "Leica Pocket Book"⁵⁴².

50MM f/2 SUMMICRON (11619)

In 1999, Leica AG in Solms produced a special edition screw-mount 50mm f/2 Summicron lens (catalog number 11619³⁵¹) exclusively for Lemon Camera, Japanese Leica dealer (see page 108 of Camera Review No. 54, published by Asahi Sonorama (Tokyo)). This lens was made with a bright chrome finish and was mathematically and optically equivalent to its contemporary Leica M counterparts²⁵².

Originally intended solely for the Japanese market, some of these lenses were returned to Germany because they were not all sold²⁵². The exact total number of lenses produced was unknown, as the Leica Camera Company did not disclose this information²⁵². Furthermore, these lenses were never listed in the official price catalogs²⁵². The motivation for producing these screw-mount lenses remained speculative²⁵². A total of 980 lenses were produced, with 65 of them shipped to New Jersey²⁵⁶.

The lens had a length of 42.5mm and weight of 0.325kg²⁵². The closest focusing distance was 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 (11621)

In 1999, Leica AG in Solms produced a special edition screw-mount 50mm f/1.4 Summilux lens (catalog number 11621³⁵⁰) exclusively for Lemon Camera, Japanese Leica dealer (see page 108 of Camera Review No. 54, published by Asahi Sonorama (Tokyo)). This lens was made with a bright chrome finish and was mathematically and optically equivalent to its contemporary Leica M counterparts²⁵².

Originally intended solely for the Japanese market, some of these lenses were returned to Germany because they were not all sold²⁵². The exact total number of lenses produced was unknown, as the Leica Camera Company did not disclose this information²⁵². Furthermore, these lenses were never listed in the official price catalogs²⁵². The motivation for producing these screw-mount lenses remained speculative²⁵². It was estimated that a total of 1,080 lenses were produced, with 65 of them shipped to New Jersey²⁵².

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

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