Chiyoda Kogaku Super Rokkor 45mm f/2.8 [C]

Chiyoda Kogaku Super Rokkor 45mm f/2.8 [C]

The Super Rokkor 45mm f/2.8 is best known as the standard lens that shipped with Chiyoda Kogaku's Minolta 35, the Leica-inspired 35mm rangefinder the company began building in May 1947 after years of making medium-format folders and twin-lens reflexes [1][2]. Its unusual 45mm focal length suited the camera's 24x32mm and later 24x33mm frame format, which was a Japanese standard at the time and yielded extra exposures per roll [1][2]. The lens earned a strong reputation early on, and period accounts held that it compared favorably with the Leitz Elmar fitted to many contemporary Leicas [1].

Optically the lens uses a coated five-element, three-group design, often described as a Heliar/Tessar hybrid, mounted in a fixed (non-collapsible) brass barrel [2][3]. It is small and light for a standard rangefinder lens, with a focus tab on a gear-like focusing ring and a front-mounted aperture ring; one common handling quirk is that turning the focus ring rotates the aperture ring as well [3]. The barrel is screw mount (LTM / M39) and the lens is rangefinder coupled, so it can be focused through the coincident-image finder of a Minolta 35 or a screw-mount Leica body, with the 50mm finder frame serving adequately for the 45mm coverage [1][3]. Minimum focus is one meter, and the glass is fully coated on its air-to-glass surfaces [3].

The lens appeared in more than one version. The earliest examples carry a small round window in the front bezel for reading the aperture, a feature dropped on later barrels; the lens is engraved Chiyoko (for Chiyoda Kogaku) rather than Minolta [2][3]. It was sold alongside other coupled Minolta 35 optics, including an 8.5cm f/2.8 Super Rokkor portrait lens and Tele Rokkor telephotos in 11cm and 13.5cm [2]. Many examples reached buyers outside Japan through Allied Occupation Forces stores, which is part of why the Minolta 35 became one of the first postwar Japanese cameras to find export success [1][2].

Optical qualities

Rendering Documented impressions are consistent though limited in number. The lens is repeatedly described as very sharp with good contrast, and being fully coated it delivers clean results in both color and black and white [3]. Collector commentary notes that Rokkor and Super Rokkor lenses are well regarded for sharpness on both their original rangefinders and on adapted digital cameras [1].

Digital use The screw mount makes the lens easy to adapt, and it is used on mirrorless and digital rangefinder bodies; its standing among adapted shooters contributes to current demand and pricing [1][3].

History

Development and Launch Chiyoda Kogaku Seiko entered the 35mm rangefinder field comparatively late, starting the Minolta 35 in May 1947 after specializing in rollfilm folders and Minoltaflex TLRs [2]. The Super Rokkor 45mm f/2.8 was created as the camera's coupled standard lens, its focal length chosen to match the camera's reduced-width frame [1][2]. The Minolta 35 line remained in production for about twelve years before being discontinued in 1959 [1].

Production Evolution The first version of the lens has a small round aperture-reading window in the front bezel; this was omitted on later barrels [2][3]. As the cameras evolved the body engraving changed (for example to 'C.K.S.' during Model B production), and the lens itself is found in several variants with minor exterior differences across its run [2][3].

Collector Notes The lens is commonly sold as a collector item and prices vary widely, from roughly the mid-hundreds upward depending on condition and version [3]. Buyers should expect the early bezel-window variant to differ from later examples, verify the Chiyoko engraving, and check the coatings for haze given the lens's age [2][3]. One reviewer cites a 34mm screw-in hood and 34mm cap as appropriate accessories, and notes that the lens uses 8 aperture blades; LeicaLensList records 9 blades, a discrepancy worth confirming on an individual example before purchase [3].

Sources

• [1] mike eckman dot com. Minolta 35 Model II (1953). https://mikeeckman.com/2020/10/minolta-35-model-ii-1953/
• [2] Camera-wiki.org. Minolta 35. https://camera-wiki.org/wiki/Minolta_35
• [3] Martin Bluhm Photography. Konica-Minolta Super Rokkor Chiyoko 45/2.8 Lens. https://martinbluhm.zenfolio.com/blog/2020/1/konica-minolta-super-rokkor-chiyoko-45/2-8-lens