Leica Summilux 50mm f/1.4 I (LTM)

Leica Summilux 50mm f/1.4 I (LTM)

The Leica Summilux 50mm f/1.4 I in Leica Thread Mount is the rare screw-mount counterpart to Leica's original 50mm Summilux. Introduced in 1959 during the final period of Leica screw-mount camera production, it carried the Leitz code SOWGE and catalogue number 11014. It shared the first-generation optical concept of the contemporary M-bayonet Summilux but was produced in far smaller numbers, making original LTM examples significantly scarcer.

The lens uses seven elements in five groups and a 16-blade diaphragm. It has an E43 filter thread, focuses to 1 metre and provides mechanical rangefinder coupling on compatible Leica screw-mount cameras. The chrome-finished lens weighs approximately 320 g, making it somewhat lighter than the contemporary M-mount version. An appropriate 50mm LTM-to-M adapter also allows normal rangefinder-coupled use on Leica M cameras.

The standard SOWGE should not automatically be equated with every Leica screw-mount 50mm Summilux ever produced. A very small number of later special-order screw-mount lenses are documented with the recomputed optical formula normally associated with the second-generation Summilux. Mount type and SOWGE identification alone are therefore not sufficient to classify an unusually late example as Version I. Serial number and production period should also be checked.

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Optical qualities

Rendering

The regular early SOWGE uses Leica's original 50mm f/1.4 Summilux optical design with seven elements in five groups. The formula developed from the optical lineage of the earlier 50mm f/1.5 Summarit while making use of newer optical glass. The first design is generally documented as producing more restrained contrast and gentler definition at maximum aperture than the recomputed Summilux design that followed. Performance becomes more controlled as the aperture is stopped down.

Contrast and color

The Summilux represented a development beyond the preceding Summarit, but the present-day behavior of individual examples depends heavily on condition. Internal haze, cleaning marks, coating deterioration and other age-related optical issues can reduce contrast and alter the apparent rendering of surviving lenses.

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History

Development and Launch

Leitz introduced the 50mm f/1.4 Summilux in 1959 as the successor to the 50mm f/1.5 Summarit. Alongside the new M-bayonet version, Leica produced a Leica Thread Mount version for users of its established screw-mount camera system.

The screw-mount lens carried the code SOWGE and catalogue number 11014. Its appearance coincided with the final years of Leica's screw-mount system, by which time the Leica M3 and M2 had established the M bayonet as the company's principal interchangeable-lens mount. This limited market explains the substantially lower production of the LTM version compared with the M-mount Summilux.

Production Evolution

The standard early SOWGE used the original seven-element, five-group Summilux optical formula. Leica subsequently recomputed the 50mm Summilux while retaining the same overall number of elements and groups.

Normal production of the Version I screw-mount lens was brief. However, Leica continued to accommodate occasional special orders, and a small number of later LTM Summilux lenses are documented from after the original production period. Some of these later lenses contain the recomputed optical design rather than Version I optics.

Published production totals for the screw-mount lens are not completely uniform between respected references. Figures in the mid-500s are commonly documented, demonstrating the rarity of the SOWGE, but a precise production total should not be treated as entirely settled where historical sources disagree.

Special Editions/Variants

Prototype and pre-series lenses connected with the development of the first Summilux are documented. Some development examples show Summarit-related engraving or other details reflecting the transition from Leica's earlier f/1.5 lens to the production Summilux.

Of particular collector importance are the unusually late special-order SOWGE lenses. Documented later examples were produced after the normal Version I period and can contain the second-generation optical formula while retaining Leica Thread Mount. These lenses should not automatically be classified as standard Version I examples simply because they carry the SOWGE designation.

No major regular-production black-finish series of the Version I SOWGE is widely documented. Standard production lenses are principally associated with a silver chrome finish.

Collector Notes

Collectors should verify the Leica Thread Mount, serial number, barrel details and production period when identifying a SOWGE. The rare later screw-mount Summilux lenses make serial-number verification particularly important because LTM mounting alone does not guarantee the original Version I optical formula.

The SOWGE/11014 should also be kept separate from the SOOME/11114 M-mount lens in catalogues and price databases. Although standard early examples share the first-generation optical design, they differ in mount, catalogue identification, weight, production rarity and compatibility.

Originality is especially important because the rarity of the LTM version makes converted, modified or incorrectly described examples potentially confusing. Buyers should verify that the screw mount is factory original rather than a later conversion and inspect the optics for haze, cleaning marks, coating deterioration, separation and internal contamination. Rangefinder coupling, focusing action and aperture operation should also be checked.

Original Leica hoods, filters, caps and packaging from the correct period can add collector interest and help document an otherwise original example.

Special editions

11014 / SOWGE: Standard Leica Thread Mount production version covered by this profile.

Late special-order SOWGE: Rare later factory LTM examples are documented with the recomputed second-generation optical formula and should not automatically be classified as Version I.