The Leitz rangefinders are among the most fascinating accessories associated with Leica, particularly since early models were developed long before the Leica camera was introduced360. Notably, the rangefinder designed for the camera, known as the FOFER, was released just one year prior to the camera's debut in 1924 (as noted in Amateur Photographer, September 10, 1924, p. 263)360. Following the launch of the Leica I Model A, Leitz continued to produce longer-range finders intended for various non-photographic applications, such as surveying, hunting, and measuring height360.
FARDI
An early type of rangefinder, the ancestor of the FOFER, was the FARDI, which operated based on the coincident-image principle (as all Leitz rangefinders would later do)360. It was introduced in 1910 and came in two models: one with a 20 cm base and another, larger model with a 40 cm base360.
The 20 cm model can accurately measure distances up to 500 meters; beyond this range, distances must be estimated360. The 40 cm model is accurate for distances up to 1000 meters, but, similarly, longer distances require estimation360.
The FARDI consists of a rectangular brass tube, measuring 25 cm in length for the model with the small base and 45 cm for the model with the large base360. At one end of the tube, there is a glass cube featuring a diagonal septum that partially transmits and reflects light360. At the other end, a right-angled prism is situated, which produces two separate images that align perfectly, allowing the user to read the distance from a fixed index on a finely engraved knurled disc360.
Both models are covered in leather and, according to Leitz, are both dustproof and waterproof—features that are not present in the FOFER model360. To enhance precision, the 20 cm FARDI can be equipped with a detachable 'Galilean' telescope (which is an optional accessory) that magnifies the eyepiece image by approximately three times360. The 40 cm FARDI comes with this telescope permanently attached360.
Long-base FARDI is illustrated below:
Gun Sight Collimator
Another early device of a similar type is a machine gun sight collimator, featuring a grey crackle finish and dating from 1912360. The marking "ZF" is a prefix that indicates a military contract order from Leitz. Unlike the FARDI, which could be held in hand, this instrument was designed to be attached to a machine gun, which is why it includes an accessory shoe360.
Leitz Rangefinders
The rangefinder introduced in 1924, ahead of the Leica I Model A camera (initially code-named FOFER and later FODIS), resembles the FARDI in design but features a significantly smaller base, measuring only 8 cm360. It is accurate for distances up to 20 meters; beyond that, estimations are necessary360. However, for distances greater than 20 meters, the distance setting of a Leica lens becomes relatively less important360.
The Leitz photographic rangefinders are categorized into two main types: long-base (10.5 cm in length) and short-base (initially 7.5 cm, later reduced to 6.2 cm)360. Among the numerous variants, the most significant examples of each type are listed below360.
Long-base Rangefinders
Length overall, 10.5cm; length of base, 8cm360
Variants360:
- Variant 1 from 1924 (code-named FOFER, then later FODIS) has a small nickel dial, 21mm in diameter. Black finish. Advertised as available from 1924 360
- Variant 2 from 1931 (code-named FOFER) is similar to Variant 1, but with a large nickel focusing dial360. Some later specimens have a chrome focusing dial, but these are rare, since by this time the FOFER had been effectively replaced by the short-base FOKOS rangefinder360.
- Variant 3 features a large dial with two scales: a black scale that ranges from 1 meter to infinity, and a red scale that ranges from 50 centimeters to 100 centimeters360. The black scale can be used independently of the close-up adaptor, while the red scale requires the adaptor for operation360. This close-focusing model is not included in any catalog and was likely part of a small production run360.
- Variant 4 shares a similar construction with Variant 2, but this model is specifically designed for cameras other than Leica, such as the Nagel Pupille360. The dial features an engraving that indicates the name of the intended camera manufacturer (for example, "N" for Nagel)360. To eliminate the need for recalibrating their rangefinders to accommodate the various cameras for which they were designed, Leitz engraved a plus sign followed by a number (e.g., +12cm)360. This indicates the additional distance that should be added to the final dial reading to obtain the correct measurement360.
A report from August 24, 1936 indicates that Wilhelm Albert developed a viewfinder for the FOFER in 1936364.
A specialized rangefinder was designed for cinematographic use (code: FOKIN), featuring a black-finished dial360. This design aligns with Leitz's policy of producing viewfinders for similar purposes360. On January 27, 1930, it was reported that Wilhelm Albert and Oskar Barnack developerd the FOKAL tilting holder for the FOKIN specialized cinematographic rangefinder364.
Among the various accessories available for these rangefinders were orange filters, a screw-on accessory shoe, a folding clip to hold the rangefinder, and a variety of leather cases360. The filters were offered in three different finishes: all-black, nickel with a black ring, and all-chrome360.
Early models of the rangefinders featured a built-in yellow filter (as did some early black Leica I models). This filter was designed to increase contrast, making focusing easier360. It was likely with the introduction of the Summar lens that the built-in yellow filter was discontinued.360 Although rangefinders equipped with the filter provided clearer images than other models, they were not satisfactory in all lighting conditions, especially under poor light, which the f/2 lens could encourage360.
In late 1935, the introduction of an orange filter (code-named ORAKO) provided users with a choice between orange and yellow360. The orange filter was reintroduced after the war (code-named OKARO) for the Leica models Ic, IIc, IIIc, If, IIf, and IIIf360.
A report from April 2, 1949, indicates that Wilhelm Albert and Mr. Bock developed a redesigned FODIS rangefinder for the Leica Ic, allowing for easier adjustments.360.
Short-base Rangefinders
Length overall, initially 7.5cm, later 6.2cm; length of base, initially 6cm, later 6 or 5.7 cm360.
Several variants exist:
- Variant 1 (code-named FOKOS) has an overall length of 7.5cm360. Nickel dial360. Swivelling shoe, enabling the rangefinder to be used horizontally and to swivel out of the way when it is designed to change the shutter speed360. For use with the Leica Standard360. From 1932360. Supplied with ever-ready case360.
- Variant 2 is similar to Variant 1, but with chrome dial360.
- Variant 3 is similar to Variant 1, but with all-chrome finish360.
- Variant 4 has an overall length of 6cm360. It is a vertical model, without a swivel foot360. Normally used with the Leica Ic, If or Ig360.
A special case was designed for these cameras to accommodate a rangefinder in its upper section360.
No specific accessories were created for the short-base rangefinders; however, most accessories designed for the long-base models can be used with them360.