TTArtisan 11mm f/2.8

TTArtisan 11mm f/2.8

The TTArtisan 11mm f/2.8 stands out as a rarity in the Leica M catalogue: a diagonal fisheye covering a 180 degree field of view across the diagonal of a full-frame sensor or frame [1]. Fisheye optics have never been common on the rangefinder system, and reviewers noted that in more than sixty years of the Leica M mount no native full-frame fisheye had existed before this lens, which TTArtisan positioned as the first of its kind for both M-mount cameras and full-frame mirrorless bodies by way of adapters [1][2]. As a diagonal rather than circular fisheye, it fills the whole frame instead of projecting a round image inside it [1].

The optical formula uses eleven elements in seven groups, with a 7-blade aperture and a minimum focusing distance of about 0.17 m [1]. The barrel is largely metal, and the cosmetic treatment deliberately echoes a Leica M lens, including a red index dot and engraved, paint-filled markings [1]. The focus ring travels roughly 90 degrees from the 0.17 m close limit to infinity, while the aperture ring is a simpler clickless design with uneven spacing between stops and a small grip tab [1]. Given the extreme focal length, depth of field is very deep, so most users rely on the distance scale rather than precise focusing, and at f/2.8 a wide zone from roughly one metre to infinity can already be held in focus [2]. The lens has no front filter thread, and a slip-on metal cap is supplied; review samples also shipped with an 11mm optical viewfinder, which is useful on a rangefinder body that cannot frame this angle of view through its own finder [1][2].

Because it is so wide, the practical experience differs from a coupled standard lens, and at least one reviewer worked with it as a scale-focus optic on the rangefinder, relying on depth of field rather than the rangefinder patch [2]. LeicaLensList records the lens as rangefinder coupled; this is the value to follow, though buyers may wish to confirm coupling behaviour on their own camera, as published accounts of focusing practice with this lens vary [2].

Optical qualities

Rendering The lens produces the strong curvilinear projection expected of a diagonal fisheye, bending straight lines that do not pass through the centre of the frame [1]. The look is the deliberate point of the lens rather than a flaw, and defishing software exists but costs significant resolution, so most users keep the fisheye effect [1]. Documented behaviour is otherwise reasonable for an inexpensive ultra-wide.

Sharpness Reviewers found the centre strong from wide open with the midframe close behind, while the extreme corners benefit from stopping down; around f/4 produces an even result across the frame when focused centrally [1]. On Sony mirrorless bodies, a degree of filter-stack-induced field curvature was noted, which is less of an issue on the lens's native rangefinder mount [1].

Bokeh and transitions The combination of a relatively fast f/2.8 aperture and the very short 0.17 m focusing distance allows some background blur if the subject is brought extremely close, and the out-of-focus rendering was described as surprisingly clean with only minor outlining [1].

Flare resistance With the sun near the centre of the frame, flare is well controlled; with a bright light source toward the corner or just outside the frame, internal reflections and some ghosting appear wide open and diminish on stopping down [1].

Distortion and vignetting Heavy barrel distortion is inherent to the fisheye projection and is by design [1]. Vignetting is comparatively mild for such a wide lens, lower than many compact rectilinear ultra-wides, though a slight green colour cast can appear in the corners against bright skies [1].

Aberrations Lateral chromatic aberration is visible at the extreme corners, in line with other fisheye lenses, but it corrects well in software and is rarely objectionable in practice [1].

History

Development and Launch TTArtisan, a Shenzhen-based maker of affordable manual-focus lenses, introduced the 11mm f/2.8 as an inexpensive way to obtain a full-frame fisheye, with reviews appearing from late 2019 onward [2]. Its significance comes from filling a long-standing gap: no other manufacturer had offered a native full-frame fisheye for the Leica M mount, and the lens was also promoted as the first full-frame fisheye designed with mirrorless cameras in mind, usable on Sony, Nikon and other systems through M-mount adapters [1][2].

Special editions No major factory special editions or variant finishes of this lens are widely documented. It is generally listed in a black finish, and TTArtisan has offered the same optic in several lens-mount versions for mirrorless cameras alongside the M-mount version [1].

Collector Notes Buyers should verify that the slip-on metal cap and, where relevant, the matching 11mm optical viewfinder are included, since the finder is the practical way to frame this angle of view on a rangefinder and may have been an optional accessory [1][2]. The lens has no filter thread, so screw-in filters are not an option [1]. One reviewer observed apparent decentering on a sample, with one side of the frame softer than the other, so checking corner-to-corner evenness on a test frame is worthwhile before purchase [2]. Note also that published descriptions of whether the lens is rangefinder coupled differ from the value recorded here; LeicaLensList lists it as coupled, and that figure takes precedence [2].

Sources

• [1] phillipreeve.net (BastianK). Review: TTArtisan 11mm 2.8 Fisheye. https://phillipreeve.net/blog/review-ttartisan-11mm-2-8-fisheye/
• [2] 35mmc. TTArtisan 11mm f/2.8 M-Mount Fisheye lens Review. https://www.35mmc.com/16/12/2019/ttartisan-11mm-f-2-8-m-mount-fisheye-lens-review/