Dallmeyer Dalrac 13.5cm f/4.5

Dallmeyer Dalrac 13.5cm f/4.5

The Dallmeyer Dalrac 13.5cm f/4.5 is a British-made long-focus rangefinder lens produced by J. H. Dallmeyer Ltd. for Leica screw-mount cameras and related systems such as the British Reid. Documented by 1950, the Leica-compatible version uses the standard M39 x 26 tpi Leica Thread Mount and was supplied in a rangefinder-coupled focusing mount manufactured by Cook & Perkins of London. Dallmeyer also produced Dalrac lenses in other mounts, including M42 and Exakta, but those versions fall outside this LeicaLensList profile.

The Dalrac uses four elements in three groups and is closely related to Dallmeyer's earlier Serrac anastigmat. Contemporary technical documentation describes the Dalrac as a Serrac-derived design with modified element spacing to improve central definition and particular attention given to color correction. The optics were Dallcoated, reflecting Dallmeyer's post-war adoption of lens coating. The LTM version uses a 36mm external filter fitting and is compatible with Leica-style A36 accessories. Its optical head can be removed from the focusing unit, an arrangement also promoted for use with Leitz focusing and reflex equipment.

Optical qualities

Rendering

Period descriptions emphasized the Dalrac's correction of astigmatism and color aberrations, with the moderate f/4.5 aperture allowing Dallmeyer to prioritize correction rather than speed. Modern use of surviving examples has shown good central definition and useful contrast, although performance varies with the condition of the coatings and internal glass.

Sharpness

The Dalrac's element spacing was reportedly adjusted from the related Serrac specifically to improve central sharpness. Modern user reports support good central definition, including use at maximum aperture, but sufficiently controlled comparative testing of multiple original examples is limited.

Contrast and color

All documented post-war Dalrac production was coated. Contemporary literature placed particular emphasis on color correction, reflecting the increasing importance of color photography during the period.

Distortion and vignetting

History

Development and Launch

The Dalrac appeared during Dallmeyer's post-war expansion into coated lenses for 35mm rangefinder cameras. It was documented in photographic literature by early 1950 and was offered as a 13.5cm f/4.5 lens for Leica-type cameras. Dallmeyer produced the optical unit, while Cook & Perkins manufactured the precision focusing mount.

Production Evolution

The Dalrac was made only in the 135mm f/4.5 specification. Its optical design was derived from the four-element Dallmeyer Serrac, with altered element spacing intended to optimize central performance and color correction.

All documented Dalrac production from this period used coated optics. The focusing mount was made by Cook & Perkins and is known with small mechanical and finish variations, including differences in the direction of focusing rotation.

Special Editions/Variants

Reid & Sigrist-marked Dalrac lenses are an important factory-associated variant. These lenses were selected or adjusted for Reid cameras and can carry the Reid name or RS monogram on the barrel.

Military versions were also supplied for British service use. Surviving examples carry Reid & Sigrist identification together with government or military markings such as the broad arrow and W6/WF inventory markings. Christie's has documented serial number 552303 as a screw-mount Dalrac made for Reid & Sigrist and sold to the British military.

No separate commercial model or catalogue number has been confirmed for the Reid or military-marked versions.

Other Dalrac lenses exist in non-Leica mounts, including M42 and Exakta. These are mount variants of the broader Dalrac family but should not be included as LeicaLensList versions of this LTM profile.

Collector Notes

Collectors should first confirm that a Dalrac is the genuine Leica-register M39 x 26 tpi rangefinder-coupled version. Dallmeyer produced the same optical design in other mounts, and later adaptations or rehousings also exist.

The Cook & Perkins focusing mount is an important originality feature. Genuine examples commonly carry the Cook & Perkins logo or identifying marks, and some authentic Reid lenses have additional Reid & Sigrist engraving. Military-marked examples are particularly distinctive and should retain consistent military, Reid and serial-number markings.

Condition issues include haze, fungus, cleaning marks and deterioration of the early coating. Auction records regularly note cloudy or cleaning-dependent optics. The rangefinder coupling should also be checked carefully because historical references note that calibration can be inaccurate on lenses that have been altered or serviced incorrectly.