73MM SCREW MOUNT LENSES

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

7.3cm f/1.9 Hektor

The first long-focus 'speed' lens from Leica is the 7.3cm f/1.9 Hektor, designed for photography in very low light conditions, such as in theaters and cafes¹⁴³. Professor Berek completed the design work in March 1931, and the lens was first offered for sale in December of that year¹⁸⁰. The six-element, three-group design by Professor Berek has gained an undeserved reputation for mediocre performance, primarily due to its well-known softness at a maximum aperture of f/1.9¹⁸⁰. This softness is a result of Professor Berek's intentional sacrifice of other design parameters to achieve maximum speed¹⁸⁰. However, overall sharpness improves significantly when the aperture is stopped down; f/4 is considered to offer optimal performance¹⁸⁰. The European aperture scale extends down to f/25, but little improvement is observed beyond f/4¹⁸⁰.

Variants

Rotary focusing mount variant (HEKON)

Introduced in 1931, the earlier version was entirely black and featured a common reversible hood, along with a rotary focusing mount¹⁰. This first variant was designed for use with the standardized Leica I Model C, where its rotating black-painted focusing mount lacked rangefinder coupling¹⁸⁰. A nickel ring displayed the distance scale, and there was no serial number or infrared index¹⁸⁰. Serial numbers were added around the 971XX mark, which makes that lenses without serial numbers are extremely rare¹⁸⁰. The introduction of the Leica II Model D in 1932 led to the incorporation of a rangefinder coupling cam around the same serial number range. The overlap of serial numbers for both coupled and non-coupled lenses suggests that some non-coupled lenses might have received these cams during factory conversions¹⁸⁰. The rotary focusing black nickel lens was coded HEKON¹⁸⁰. In 1932, Leitz launched the Leica II Model D with its coupled lenses, leading to the replacement of these early configurations with the rangefinder-coupled HEKONKUP version³⁰.

Parallel focusing mount variant (HEGRA)

The later version of this lens was introduced around 1936 and features a parallel focusing mount¹⁰ called HEGRA. The development of this parallel focusing mount was prompted by the introduction of the Agfa color system in 1933¹⁸⁰. Agfa utilized a lenticulated film emulsion surface with tricolor taking (FARBA) and projection (FARPU) filters; the red, green, and blue glass stripes of the filter needed to be precisely aligned parallel to the film lenticulation¹⁸⁰. The fast speed of the 7.3cm f/1.9 Hektor made it an ideal lens for the Agfa system¹⁸⁰. The front of the parallel mount does not rotate during focusing, and a small stud near the front of the lens ensures proper orientation of the Agfa filters each time. The filters restrict the lens to an effective aperture of f/2.9¹⁸⁰. HEGRA version had locating pins for the filters²⁶⁶ to accommodate the early Agfa color photography system²⁶⁶. It is easily identifiable by the wide chrome focusing ring that separates the black lens mount¹⁰. This version also comes with a reversible hood and is optically identical to the earlier model¹⁰. Once Kodachrome and Agfa color transparency films became available around 1936, the need for the more complex parallel mounts diminished, and the last models of the 7.3cm f/1.9 Hektor returned to the rotating mount HEKON²⁶⁶. This HEKON mount allowed the lens head to be removed for use on close-up devices, while the HEGRA lens head was fixed in place²⁶⁶. By 1937, chrome replaced nickel on the focusing scale, and black paint was substituted for the ring at the rear of the lens¹⁸⁰. An infrared focusing index was also included at this time¹⁸⁰. The black/chrome lens was designated the code HEKON-CHROM¹⁸⁰. In 1932, Leitz launched the Leica II Model D with its coupled lenses, leading to the replacement of these early configurations with the rangefinder-coupled HEGRAKUP version³⁰.

Variants Pictured

Three variants of the 7.3cm f/1.9 Hektor in rotary mount (HEKON). From Left to Right:¹⁸⁰
1. Type 3 with Black nickel finish, rangefinder coupling and no infrared index at serial number 971XX¹⁸⁰
2. Type 5 with Black nickel finish, rangefinder coupling and no infrared index at serial number 129XXX¹⁸⁰
3. Type 10 with Black chrome finish, rangefinder coupling and infrared index at serial number 437XXX¹⁸⁰

7.3cm f/1.9 Hektor Variants:¹⁸⁰

Type	Focus	Finish	Infrared	Weight	Rangefinder Coupling	Serial #
1	Rotary	Black/ Nickel	No	?	No	None
2	Rotary	Black/ Nickel	No	?	No	971XX
3	Rotary	Black/ Nickel	No	500	Yes	971XX
4	Parallel	Black	No	475	Yes	972XX
5	Rotary	Black/ Nickel	No	493	Yes	129XXX, 141XXX
6	Rotary	Black/ Nickel	Yes	?	Yes	?
7	Parallel	Black / Chrome	No	475	Yes	1665XX
8	Parallel	Black / Chrome	Yes	475	Yes	1669XX
9	Parallel	Black / Chrome	Yes	491	Yes	235XXX, 377XXX
10	Parallel	Chrome	Yes	?	Yes	?
11	Rotary	Black / Chrome	Yes	493	Yes	437XXX, 538XXX
12	Rotary	Black / Chrome	Yes	493	Yes	5384XX, Coated

Three variants of the 7.3cm f/1.9 Hektor in parallel mount (HEGRA) from left to right¹⁸⁰:

Type 4 with all black finish, rangefinder coupling and no infrared index at serial number 972XX. This first version of the HEGRA lens featured an all-black paint finish and was identified by the serial number 972XX. This version is extremely rare and may have been a factory modification of unsold uncoupled rotary mount lenses. The black paint on the focusing ring wore off quickly with use, prompting Leitz to replace it with a bright chrome finish. A nickel finish on the focusing ring has been reported¹⁸⁰.
Type 7 with Black/Chrome finish, rangefinder coupling and no infrared index at serial number 1665XX; The second and third versions of the HEGRA also lacked an infrared (IR) focusing mark¹⁸⁰.
Type 8 with Black/Chrome finish, rangefinder coupling and infrared index at serial number 1669XX. The small stud visible near the front of the type 8 lens provides proper orientation of the Agfa color filters. The fourth version, however, incorporated this IR mark, beginning at approximately serial number 1669XX. Aside from this addition, the fourth version was otherwise identical to its predecessors¹⁸⁰.

Quantity

According to the list of lens serial numbers published in Appendix 2 of Puts' Leica Chronicle, the first batch of 7.3cm f/1.9 Hektor began at 94140, followed by a second batch that started at 96492³⁰⁵. The next recorded block of lens numbers was 96611 – 97118, which had been allocated to 9 cm Elmars³⁰⁵. This was followed by a third batch of 7.3cm f/1.9 Hektor numbered from 97185 onward³⁰⁵.

Accessories to go with the lens

One of the advantages of the 7.3cm f/1.9 Hektor was its relatively small and light design²⁶⁶. It was well-suited for use with rangefinder cameras starting in 1932, featuring an enlarged rangefinder image with diopter control starting in 1933²⁶⁶. From 1935 onward, it offered good direct viewfinding for available light subjects like sports, theater, and journalism, facilitated by the SAIOO Albada folding sport finder²⁶⁶. SAIOO may be difficult to find¹⁴³.

The 7.3cm f/1.9 Hektor front cap, known as ORXDO, is noteworthy because it fits only the reversed lens hood (FGHOO) ¹⁸⁰. The existence of a chrome ORXDO lends support to the theory that a small run of all-chrome 7.3cm f/1.9 Hektor lenses was produced¹⁸⁰.

The 7.3cm f/1.9 Hektor came with a reversible hood for storage, and the lens cap was designed to fit over it²⁶⁶. Push-on filters were introduced in 1933, but early push-on filters for the 50mm Xenon were also compatible, such as the "Gelbfilter 2" code-named XOOCN²⁶⁶. Late models of the 7.3cm f/1.9 Hektor had a threaded front flange compatible with E39 screw-in filters, still used on several current lenses²⁶⁶. Early 7.3cm f/1.9 Hektor lenses had a flange that appeared threaded but, upon closer inspection, were merely parallel grooves designed to reduce reflections entering the lens²⁶⁶. Although the interior diameter was still 39mm, E-39 filters could not be mounted due to the absence of helical threads²⁶⁶.

Collector’s Corner

Lenses with serial numbers under 100000 are especially rare¹⁸⁰.

An all-chrome variant has been reported in Japan¹⁸⁰. The brushed chrome HEGRA might be a special-order item or a unique factory conversion¹⁸⁰.

Military

In 1940, a lens coating was applied to some of the last batches of the black/chrome 7.3cm f/1.9 Hektor lenses, specifically intended for the Kriegsmarine¹⁸⁰. These coated lenses were engraved with the Reich Adler and "MF" navy markings, and they carry a specific serial number¹⁸⁰. They are very rare and seldom seen today¹⁸⁰.

Closing Remarks

For many years, the development of the 7.3cm f/1.9 Hektor was regarded by Leitz as one of their outstanding optical achievements, and it remained the fastest lens in the Leitz catalog until the introduction of the 5cm f/1.5 Xenon in 1936¹⁸⁰. The launch of the 8.5cm f/1.5 Summarex in 1943 ultimately marked its decline¹⁸⁰. Throughout its twelve years of production, the 7.3cm f/1.9 Hektor was considered the premium lens offering for the Leica, with the highest quality of construction maintained¹⁸⁰. Leitz consistently sought a relatively high selling price for this prestigious lens, which, along with its specialized function, resulted in modest sales totaling 7225 units¹⁸⁰.