Carl Zeiss Sonnar T* 85mm f/2 ZM

Carl Zeiss Sonnar T* 85mm f/2 ZM

Among the thirteen lenses Zeiss released in its M-mount ZM line, the Sonnar T* 85mm f/2 stands out as a rarity. It was one of only two ZM lenses built in Germany rather than by Cosina in Japan, the other being the Distagon 15mm f/2.8, and its complexity is the reason it stayed in Oberkochen rather than going to the Japanese production line [1]. Estimates often cite a production run of around 600 units, a figure widely repeated but never confirmed by Zeiss, which has made the lens an unusually scarce object on the used market[2].

The optical layout uses six elements in six groups and was described by Zeiss as the first M-mount telephoto with floating elements, drawing on the company's cine lens experience and paired with a nonlinear rangefinder coupling mechanism. Despite the Sonnar name and the close attention to wide-open performance, it is not an apochromatic design like Leica's APO-Summicron 90mm. The barrel is all metal with a smooth focus ring, an aperture ring running from f/2 to f/16 in half stops, ten aperture blades, a 58mm non-rotating front filter thread, and a minimum focus distance of one meter. It is rangefinder coupled and couples on Leica M bodies, and reviewers note it balances well on cameras such as the M9 and M Typ 240 despite its unusual shape. The lens hood (Zeiss part number 1365-668) was an optional accessory sold separately rather than included.

The lens was assigned product number 1355 732 and shipped only in black. It was announced alongside the Zeiss Ikon rangefinder at Photokina in 2004, but manufacturing difficulties tied to its floating-element design caused repeated delays, so deliveries did not begin until 2007, and it was quietly discontinued in 2011. Both the optical and mechanical assemblies proved hard to produce even for Zeiss in Germany. A recurring reliability complaint among owners is the so-called Zeiss wobble, a play that can develop in the barrel and that has often required return to Zeiss for repair.

Optical qualities

Rendering The Sonnar 85mm f/2 is documented as a high-resolution lens with strong sharpness and micro contrast, to the point that it is sometimes called one of the highest-resolving M-mount lenses, though this comes with notable chromatic aberration. Performance can be brilliantly sharp wide open when focus is placed precisely, and it tightens further at f/4 to f/8. Its character is a high-resolving, contrasty draw rather than a soft classic Sonnar look.

Bokeh and transitions At f/2 to f/4 the lens has a recognizable signature, but reviewers describe its background blur as inconsistent and at times messy, with a more two-dimensional rendering than some comparable Zeiss portrait lenses. Wide open at close range the plane of focus is very shallow.

Aberrations Chromatic aberration is the lens's main weakness. Blue or purple fringing appears in backlit and high-contrast situations and near defocused highlights wide open, and it diminishes when stopped down to about f/2.8.

Distortion and vignetting The lens shows a fair amount of vignetting wide open that largely clears by f/4. Because the telephoto design sends light to the sensor at near right angles, it avoids the color shift and edge tinting seen with some wide rangefinder lenses on digital bodies.

History

Development and Launch Zeiss presented the Sonnar 85mm f/2 ZM together with the Zeiss Ikon camera as part of the new ZM system at Photokina in 2004. It was intended as a cornerstone fast telephoto for the range, with a launch price around 2,800 euros, only slightly below Leica's APO-Summicron 90mm ASPH. After repeated postponements caused by the difficulty of manufacturing its floating-element optical system, the first units did not reach buyers until 2007.

Production Evolution Unlike most ZM lenses, which were outsourced to Cosina in Japan, the 85mm was built at the Zeiss plant in Germany because of its optical and mechanical complexity. It remained in the catalogue only a few years before being discontinued in 2011, reportedly affected by high price, production cost and production problems.

Special editions No major factory special editions, military versions or alternative finishes of the Sonnar 85mm f/2 ZM are widely documented; it was offered as a single black, M-mount version.

Collector Notes Identification points include the front ring engraving Carl Zeiss Sonnar T* 2/85, the product number 1355 732, and the 58mm non-rotating filter thread. The optional hood (Zeiss 1365-668) is frequently missing, so its presence is worth confirming. Buyers should check the barrel for the Zeiss wobble, since several owners have had to send copies back to Zeiss for service. The small reported production of roughly 600 units helps explain its scarcity and rising collector interest, though that quantity has never been officially confirmed.