Leica Elmar 50mm f/3.5 LTM Red Scale (1951)

Leica Elmar 50mm f/3.5 LTM Red Scale (1951)

The Leica Elmar 50mm f/3.5 LTM Red Scale is a collapsible standard lens introduced in 1951 for Leica screw-mount rangefinder cameras. It represents the final major form of the classic f/3.5 Elmar in Leica Thread Mount and is distinguished by red-filled depth-of-field markings, revised scale placement and a late coated optical configuration. It remains historically important as the last major development of the compact Elmar design before the faster Elmar 50mm f/2.8 replaced it in Leica's normal-lens range [1][2].

The lens uses a four-element, three-group optical construction and a ten-blade diaphragm operating from f/3.5 to f/22. Its chrome-plated brass barrel collapses into compatible Leica screw-mount camera bodies for transport. The focusing mount is rangefinder coupled, locks at infinity and focuses down to 1 metre. Filters and accessories attach through the A36 clamp-on standard rather than a conventional 36mm threaded filter mount [1].

The Red Scale version should be separated from the earlier black-scale chrome Elmar. Collector references describe a recomputed design beginning around serial number 905000, accompanied by changes in optical glass and element curvature. The visible identification changes include red depth-of-field figures and the reversal of the focusing-distance and depth-of-field scale positions. However, black-scale and Red Scale production overlapped, so production year or serial number alone should not be used without inspecting the physical markings [2][3].

Leica's historical overview states that the interchangeable screw-mount Elmar remained in production until 1959. Specialist serial-number research has identified lenses described as Red Scale as late as serial number 1812xxx in 1961. Because the exact division between late LTM production, M-mount production and later deliveries is not completely consistent across references, 1959 is used as the database end year for this LTM entry [2][4].

Optical qualities

Rendering

The Red Scale Elmar retains the compact four-element, three-group architecture associated with the classic Elmar family. Leica describes the 50mm f/3.5 Elmar as producing good central definition at full aperture, with weaker outer zones that improve when the lens is stopped down [4].

The degree to which the Red Scale computation improved performance over the preceding coated black-scale Elmar remains debated. Erwin Puts documented changes in element curvature and reported glass specifications, but cautioned that small curvature changes alone do not necessarily prove a substantial performance difference [3].

Sharpness

The lens is strongest in the central image area at wider apertures. Stopping down improves the outer field and overall uniformity. Specialist historical references place peak general performance around f/8, although the condition and optical alignment of individual surviving examples can materially influence results [2][4].

Contrast and color

The Red Scale Elmar was produced as a coated lens. Its coating and limited number of air-to-glass surfaces support better contrast in difficult lighting than an early uncoated Elmar. Actual performance depends heavily on coating condition, internal haze, cleaning damage and previous servicing.

Flare resistance

The A36 FISON hood is the period accessory normally associated with this lens. Hood use is advisable because front-element cleaning marks, coating deterioration and internal haze can reduce contrast and increase veiling flare.

Digital use

The lens can be mounted on a Leica M camera with a correctly manufactured 50mm LTM-to-M adapter. Because it is collapsible, clearance should be checked before retracting the barrel into any digital or film M body. The lens should not be collapsed when compatibility is uncertain.

History

Development and Launch

The original 50mm f/3.5 Elmar design became Leica's principal standard lens during the screw-mount era. In 1951 Leitz introduced the form now commonly called the Red Scale Elmar, beginning around serial number 905000 according to specialist collector research [2].

The revised lens retained the established 50mm focal length, f/3.5 maximum aperture, collapsible construction and one-metre minimum focusing distance. The most visible changes were the red-filled depth-of-field figures and the reversed placement of the distance and depth-of-field scales [1][2].

The lens was announced in the United States in the Spring 1953 issue of Leica Photography. The announcement presented it with the Leica If, and specialist research records the camera-and-lens combination under the Leitz code OEINO [2].

Production Evolution

Early Red Scale lenses were produced in Leica Thread Mount with metric or foot distance scales. Some collector references distinguish early examples by a diamond-shaped focus index and later examples by a triangular index. These are identification variations within the Red Scale family rather than separate optical models.

Serial-number records show that black-scale and Red Scale lenses overlapped during 1952. Documented Red Scale production blocks include serial numbers in the 1010201 to 1015000, 1045001 to 1050000 and several later 1952 and 1953 batches [1].

Later production continued alongside the native Leica M-bayonet Elmar. Screw-mount examples must therefore be distinguished from M-mount lenses and from LTM lenses carrying a removable M adapter.

Special Editions/Variants

Standard production included metric and foot scales, together with minor engraving and scale-index variations. These are regular production variants and should not receive a Special Edition tag.

An Esercito Italiano version with Italian Army engraving is documented. Rare black-finished Elmars with white engravings were also made to accompany a limited group of black Leica IIIf cameras. No separate numerical model number is confirmed for either variation [1][2].

Older Elmars could be returned to Leitz for coating, repolishing, recalibration or mechanical updating. A lens with modified red markings or a replacement barrel may therefore not retain its original optical cell or original production appearance.

Collector Notes

A genuine production Red Scale Elmar normally displays red-filled depth-of-field markings and the reversed scale arrangement associated with the late version. The serial number is engraved in small figures near the front aperture-control area and should be inspected with magnification.

Collectors should not classify a lens solely by its year. Red Scale and black-scale examples overlap in documented serial-number blocks, and Leitz offered factory servicing that could alter coatings, engravings or mechanical components.

The lens should be inspected for front-element cleaning marks, coating damage, internal haze, fungus and separation in the cemented rear group. The collapsible tube should extend smoothly and lock firmly. The infinity lock, focusing helicoid, aperture tab and rangefinder cam should operate without excessive resistance.

Original accessories include the FISON A36 clamp-on hood, A36 filters, front and rear caps and period Leica cases. Accessories can add collector value, but they do not establish the authenticity or production version of the lens itself.

Special editions

• Esercito Italiano engraving: Documented Italian Army-marked variant. Separate catalogue number not confirmed.
• Black-finished IIIf-matching version: Rare black factory finish with contrasting engravings. Separate catalogue number not confirmed.
• Metric and foot scales: Regional production variations, not Special Editions.
• Diamond and triangle index forms: Collector identification variations within Red Scale production, not separate database entries.
• Factory-updated earlier Elmars: Service conversions should not automatically be classified as original 1951 Red Scale production.

Sources

• [1] Leica Wiki. Elmar (II) f=5 cm 1:3.5. https://wiki.l-camera-forum.com/leica-wiki.en/index.php/Elmar_%28II%29_f%3D_5_cm_1%3A3.5
• [2] Summichronica. Leica Screw Mount Lenses, 50mm. https://www.summichronica.com/screw-mount-lenses-50mm
• [3] Erwin Puts. Older M Lenses, Elmar 3.5/50 Red Scale. https://www.imx.nl/photo/leica/lenses/page86.html
• [4] Leica Camera. The 50 mm Elmar, An Enduring Classic Leica Lens. https://leica-camera.com/en-US/blog/photography/carl-merkin-50mm-elmar
• [5] Leitz Photographica Auction. IIf/IIIf Lot with Red Scale Elmars. https://www.leitz-auction.com/en/IIf-IIIf-Lot/AI-23-10904