MS-Optics Sonnetar 50mm f/1.1

MS-Optics Sonnetar 50mm f/1.1

The Sonnetar 50mm f/1.1 is the lens that established Sadayasu Miyazaki and his one man workshop in the wider rangefinder community, and it remains his best known design [3]. Rather than chasing optical perfection, it revives the classic Zeiss Sonnar layout in an unusually small and very fast package, and reviewers consistently treat it as a character lens rather than a clinical performer [1]. When it was announced in 2012 it was offered as a multicoated f/1.1 normal lens that was far more compact than rivals such as the Leica Noctilux or the Canon 50mm f/0.95, which is a large part of its appeal [4][2].

The optical formula is built from five elements in four groups, an all spherical arrangement descended from the Sonnar, which keeps the lens both fast and light at around 195 g. The iris uses 14 rounded, clickless blades and was described at launch as a German made unit, and the glass carries a two layer multicoating. Handling is idiosyncratic: the lens focuses by rotating the whole front section while only the mount and distance scale stay fixed, so the de-clicked aperture and the focus can be easy to disturb together, a quirk reviewers note alongside the smooth damping. A small focus pin on the underside helps with this, and the lens is supplied with a screw-in focusing lever, a short metal hood and several caps. At the rear is a coma adjuster, a ring with marked positions that shifts the rear group to fine tune the effective focal length and spherical aberration, since the design is nominally around 51.6 to 51.7 mm; it can also be used to fine tune calibration on a given body. Filter threading is unusual, with a normal thread, a reverse thread that also accepts the hood, and a further thread in the hood itself.

As with all MS-Optics products, the Sonnetar is assembled by a single person in low volume, which explains both its limited availability and its rising secondhand prices. The barrel is lightweight aluminium and the build is best described as handmade rather than refined, something owners tend to accept as part of its charm. The lens has appeared in M and LTM mount forms, in black finish.

Optical qualities

Rendering The Sonnetar produces the kind of imagery associated with fast Sonnars: low contrast and a soft glow wide open, with that glow clearing as the lens is stopped down.

Sharpness Wide open the centre is soft and glowing from spherical aberration, sharpening noticeably from roughly f/1.5 to f/2, while the corners stay soft and never fully resolve until well stopped down. Field curvature is present and can affect both sharpness and the look of the out of focus areas.

Bokeh and transitions The background rendering is strongly Sonnar in character, smooth in some scenes and busier in others depending on distance, background and aperture, and at the widest settings it can become quite swirly before calming down on stopping down.

Flare resistance Flare is a real consideration; the supplied hood helps but does not eliminate it, and one detailed test describes veiling flare as a significant weakness with point light sources producing artefacts.

Distortion and vignetting Vignetting is heavy wide open, with corners losing two to three stops of light, in keeping with the fast Sonnar formula.

Aberrations Expect focus shift typical of Sonnar designs, most noticeable in the middle apertures, along with longitudinal chromatic aberration that is only moderately corrected.

History

Development and Launch The Sonnetar 50mm f/1.1 was announced in September 2012 through Japan Camera Hunter as the latest design from Miyazaki of MS-Optical, following his earlier Perar pancake lenses. It was presented as a multicoated lens using Tantalum glass with a Sonnar based 5 element, 4 group layout, a German made 14 blade clickless iris and a rear coma adjustment ring with infinity, 4 m, 2 m and 1 m settings. Miyazaki cited optimum performance around f/1.6 to f/2. The first run sold out on pre-order, reflecting the demand for a compact, fast normal lens of this type.

Production Evolution The maker's name appears both as MS-Optical-R&D and later simply MS-Optics, which accounts for the different spellings seen on lenses and in reviews. Because each lens is hand built in small numbers, individual examples can vary, and one reviewer observed signs of element decentering in a sample, something to be aware of with low volume handmade optics.

Special editions No widely documented factory special editions of the Sonnetar 50mm f/1.1 are recorded beyond the standard black M and LTM versions.

Collector Notes Buyers should account for the lens's eccentric handling, including the rotating focus barrel, the de-clicked aperture and the multiple caps and screw-in focusing lever that are easy to misplace. The rear coma adjuster should be checked and set correctly for accurate use on a rangefinder, as misadjustment will throw off focus. Given the handmade construction, it is worth checking for decentering and overall optical condition before purchase, and noting that demand from collectors has pushed used prices upward.