Ross Xtralux 13.5cm f/4.5

Ross Xtralux 13.5cm f/4.5

Among the small group of British lenses ever offered in Leica screw mount, the Ross Xtralux 13.5cm f/4.5 stands out as one of the harder-to-find members of a short-lived family. Ross of London built it as part of the Xtralux range, a set of screw-mount optics that the firm introduced alongside the Reid, the British Leica copy made by Reid & Sigrist [1][2]. As a 135mm telephoto, it sat at the long end of that line, above the 50mm and 90mm Xtralux lenses, and it appears in collector catalogues finished in chrome with a black-and-chrome barrel [2].

The lens is a substantial all-metal piece in the L39 thread mount, with a length and weight that reflect the long telephoto construction typical of 135mm rangefinder lenses of the period. It is not rangefinder coupled, so on a Leica or Reid body it is used by setting distance on the focusing scale rather than through the camera's coupled rangefinder, a common arrangement for longer focal lengths from independent makers of the era [2]. Ross gave the Xtralux line coated optics, in keeping with the late-1940s shift to coated lenses across the British and Continental industries [3].

Documentation on individual variants of the 135mm version is thin. Collector references list it simply as the 135/4.5 Xtralux in chrome, without the multiple barrel or coating revisions recorded for some of its siblings, and surviving examples turn up mainly through British auction houses rather than in large numbers [2][4]. Because the Xtralux name was applied across several focal lengths, buyers should confirm the focal length and aperture engraving rather than rely on the family name alone [2].

Optical qualities

Rendering Reliable published testing of this specific lens is scarce, so its rendering is best described only in general terms. It is a coated, moderate-aperture telephoto from the late 1940s, and like other Ross optics of the period it was built to deliver good central definition for portrait and short-telephoto work [3]. Detailed, repeatable observations on its sharpness, contrast, bokeh, flare behaviour, or performance on digital bodies are not well documented, and any stronger claims would be speculative.

History

Development and Launch Ross was a long-established British optical company, founded in 1830 and known for camera lenses and binoculars, with an early and close association with Carl Zeiss of Jena; Ross held licences to make certain Zeiss designs for the British Empire, and Zeiss in turn licensed some Ross patents [1]. In 1948 or 1949 the firm was merged into Barnet Ensign, the successor of Houghton-Butcher, to form Barnet Ensign Ross Ltd., which became Ross Ensign Ltd. in 1954 [1]. It was around this same post-war period that Ross produced the Xtralux screw-mount range, released together with the Reid, the British-built Leica copy, giving the new domestic rangefinder system a set of native lenses [1][2].

Production Evolution The Xtralux family spanned several focal lengths and barrel styles, including a collapsible 50mm f/2, a rigid 50mm f/3.5, a 90mm f/3.5, and the 135mm f/4.5, the last of which is recorded in chrome with black-and-chrome finish [2]. Compared with the shorter lenses, where collectors note both coupled and uncoupled examples and different finishes, the 135mm appears in a more limited form, and granular records of optical or coating revisions specific to it are lacking [2].

Special editions No widely documented factory special editions, military variants, or alternative regional names are recorded for the 135mm Xtralux. It is generally encountered as a standard chrome production lens [2][4].

Collector Notes The 135mm Xtralux is a genuinely scarce British LTM lens and is typically described as such when it surfaces at auction; one example, serial number 235410, sold through a UK saleroom and was catalogued as a rare British screw-mount lens complete with front and rear caps [4]. Because the Xtralux name covers multiple focal lengths and apertures, verify the engraving for the 13.5cm f/4.5 designation, confirm the lens is genuinely in L39 thread, and check the coated front element for haze, cleaning marks, or coating wear, all common in lenses of this age [2][4]. As an uncoupled telephoto, it does not link to a camera's rangefinder, so this should be expected rather than treated as a fault [2].

Sources

• [1] Camera-wiki.org. Ross. https://camera-wiki.org/wiki/Ross
• [2] Camerapedia (Fandom). 39mm screw lenses. https://camerapedia.fandom.com/wiki/39mm_screw_lenses
• [3] Camera-wiki.org. Ross Xpres. https://camera-wiki.org/wiki/Ross_Xpres
• [4] Chiswick Auctions. Lot 177 - A Ross London 13 1/2cm Xtralux f/4.5. https://www.chiswickauctions.co.uk/auction/lot/177-a-ross-london-13-12cm-xtralux-f45/?lot=164847&sd=1