Tanaka Kogaku Tanar 50mm f/2.8

Tanaka Kogaku Tanar 50mm f/2.8

The Tanar 50mm f/2.8 was a mid-range standard lens from Tanaka Kogaku, a short-lived Kawasaki maker whose Tanack rangefinder cameras and Tanar lenses were produced for only about six years before the company folded in 1959 [1]. It sat between the budget f/3.5 and the faster f/2 in the Tanar standard line, and like the rest of that line it was sold mostly as the lens fitted to a Tanack body rather than as a separate purchase [1]. Its modest aperture, combined with the company's small output and early demise, has made surviving examples uncommon and of interest mainly to collectors of 1950s Japanese rangefinder equipment [2].

Optically the lens uses a Tessar formula of four elements in three groups, the same basic design as the cheaper f/3.5 Tanar, and Tanaka's own tests reported identical resolution figures for the two lenses [1]. It is a screw-mount (LTM/M39) lens with a rigid barrel; the f/2.8 was never offered in a collapsible mount [1]. All Tanar lenses use a straight helical so the front of the barrel does not rotate during focusing [1]. The aperture scale runs from 2.8 to 22, and on the earliest examples an intermediate index for 3.5 was also engraved [1]. The lens couples to the Tanack rangefinder, though distances closer than the standard near limit on the close-focusing variant are uncoupled and marked separately on the scale [1].

Several distinct versions exist. The first lenses, released in spring 1954 for the Tanack 35 and later fitted to the IIIS, have an all-chrome rigid barrel focusing to about 3.5 feet, with serial numbers seen in the 45xxx, 46xxx, 52xxx and 87xxx ranges [1]. For the Tanack IV-S the lens was modified with closer focusing to 1.5 feet, the aperture ring reversed in direction and the 3.5 index dropped, with numbers in the 57xxx range [1]. It was then updated as the chrome Tanar H.C. 5cm f/2.8, where the front bezel gained a black background and a red H.C. marking that the maker associated with hard coating, although it is not confirmed whether the optics actually changed or the change was cosmetic [1]. A black-and-chrome H.C. finish followed around early 1957, and a final restyled version with an exposure-value scale and a green 47.5-degree angle-of-view marking appeared in very small numbers for the Tanack V3 in early 1959 [1].

Optical qualities

Rendering Documented information specific to the f/2.8 is limited. Tanaka's factory testing reported the same resolution as the f/3.5 Tessar version, around 80 lines per mm at the center and 40 at the corners at an unspecified aperture [1]. As a coated four-element Tessar of its era, it would be expected to perform best stopped down, but published independent reviews of this particular lens are scarce, and firm claims about its bokeh, contrast or flare behavior are not well supported in the sources.

History

Development and Launch Tanaka Kogaku, based in Kawasaki, entered the crowded Japanese rangefinder market relatively late with its Tanack cameras and Tanar lenses [2]. The f/2.8 standard lens was released in spring 1954 for the Tanack 35 and became one of the three apertures (alongside f/3.5 and f/2) offered as the standard optic across the Tanack line [1]. The f/2.8 commanded only a small premium over the f/3.5, which helped make it a more popular choice than the slow lens [1].

Production Evolution Over roughly five years the lens passed through an all-chrome early barrel focusing to 3.5 feet, a close-focusing IV-S version to 1.5 feet, the chrome and then black-and-chrome H.C. versions with the red coating mark, and a final V3-era barrel with an exposure-value scale [1]. By mid-1957 the H.C. lens was listed separately at ¥8,500 [1]. The last V3 version was made in limited quantities, with the only confirmed serial number carrying a "28" prefix that appears to encode the maximum aperture [1].

Special editions No major factory special or military editions of the f/2.8 are widely documented. The principal variations are finish and barrel changes rather than distinct editions, although at least one chrome and one black H.C. example are recorded with the distance scale engraved in meters, an unusual feature on a Tanar that otherwise used feet [1].

Collector Notes Buyers should confirm which version they are looking at, since the chrome, H.C. chrome, black-and-chrome and late V3 barrels differ in markings, focusing range and aperture-ring direction [1]. The red H.C. on the bezel denotes the company's coating designation rather than a separate model, and it is uncertain whether it reflects a genuine optical change [1]. The verified specification of nine aperture blades and a minimum focus of about 1.07 m is consistent with the standard rigid version focusing to roughly 3.5 feet; collectors should note that the dedicated close-focusing IV-S variant instead reaches 1.5 feet [1]. Because Tanar lenses were usually sold mounted on a body, matching of lens and camera serial ranges and originality of finish are worth checking before purchase [1].

Sources

• [1] Camerapedia. Tanar lenses. https://camerapedia.fandom.com/wiki/Tanar_lenses
• [2] Leica Lens List. Tanaka Kogaku Lenses. https://www.leicalenslist.com/makes/tanaka-kogaku