7artisans 28mm f/5.6

7artisans 28mm f/5.6

The 7artisans 28mm f/5.6 arrived in 2022 as one of two near-simultaneous budget answers to the costly Leica Summaron-M 28mm f/5.6, the other being the unrelated TTArtisan lens of the same specification [1][2]. Despite sharing the focal length and aperture with that classic, 7artisans took its own path mechanically and optically rather than imitating the vintage Leica barrel, and the lens is sometimes marketed under the maker's "Wen" series name [2]. Reviewers framed it less as a serious optical achievement and more as an inexpensive, lightweight walk-around prime: at launch it sold for around 299 US dollars, roughly a tenth the price of the re-released Leica [1].

Optically the lens uses a six-element, four-group design, which sources note is one element fewer than the rival TTArtisan and includes high refractive index and low dispersion glass intended to help control aberrations [1]. It is fully manual with a metal barrel, engraved and paint-filled barrel markings, and an eight-bladed iris that stays close to circular at the click-stopped full apertures [2]. Unlike the Leica and TTArtisan lenses, which use a focusing lever, the 7artisans places conventional aperture and focus rings around the barrel; the focus ring turns roughly 120 degrees across its range and the aperture ring clicks in full stops from f/5.6 to f/22 [2]. The lens is rangefinder coupled throughout its focus range and minimum focus is the same 1 metre shared by its rivals [1][2]. A 35.5 mm filter thread sits at the front, an uncommon size for which a step-up ring is usually the practical solution, and a slip-on metal hood is supplied [2].

The lens is offered only in a black finish, in keeping with 7artisans' M-mount lineup [1]. It should not be confused with the maker's much heavier and brighter 28mm f/1.4, nor with the TTArtisan 28mm f/5.6, which looks closer to the original Summaron but uses a different optical formula and a six-bladed iris [1][2].

Optical qualities

Rendering As a slow f/5.6 wide-angle, the lens is not intended for shallow depth of field work, and reviewers treat it primarily as a compact stopped-down landscape and street optic [2]. Documented behaviour is mixed: center and midframe resolution is described as good from f/5.6, but the corners only reach their best around f/11, and on high-resolution mirrorless sensors the corners never become truly sharp [2].

Distortion and vignetting Testing found low but wavy distortion that can be awkward to correct where straight lines run through the frame, with no correction profile available at the time of review [2]. Corner shading was measured at about 2.4 EV wide open, easing to roughly 1.6 EV stopped down, with a slight bluish-greenish color cast toward the corners on a Leica M10 [2].

Flare resistance and aberrations Flare resistance is described as inconsistent: ghosts are uncommon but contrast can drop with a bright light source near the frame, and some ring flare appears at f/5.6 [2]. Coma is more pronounced than expected for a slow wide-angle and largely clears by f/11, while both lateral and longitudinal chromatic aberration are very low, the latter limited by the modest maximum aperture [2].

History

Development and Launch 7artisans announced the M28mm f/5.6 in May 2022 as an affordable full-frame M-mount prime, positioning it directly against the Leica Summaron-M 28mm f/5.6 and the recently launched TTArtisan equivalent [1]. It was the company's second 28mm lens for full-frame M-mount and weighs about a quarter as much as its earlier, much faster 28mm f/1.4 [1]. The six-element, four-group layout was likened to the lineage of the original screw-mount Summaron-derived design of the mid-1950s, though the implementation is modern [1].

Special editions No major factory special editions, military or export variants, or alternative finishes are widely documented; the lens is sold only in black [1].

Collector Notes The most cited quirk is that the lens brings up the 35mm framelines rather than the correct 28mm lines on Leica M bodies, which reviewers regarded as a notable shortcoming [2]. The barrel also carries an infinity lock that must be released to focus, a design some users find inconvenient [2]. Buyers should account for the unusual 35.5 mm filter thread and verify the presence of the supplied slip-on hood, which can contact the aperture ring if pushed on too far [2]. As an inexpensive recent lens, sample centering is worth checking, a general caution raised in discussion of low-cost manual optics [2].

Sources

• [1] Popular Photography (Mike Tomkins). 7artisans takes on the Leica Summaron-M 28mm f/5.6 for a tenth of the cost. https://www.popphoto.com/news/new-7artisans-28mm-m-mount-lens/
• [2] phillipreeve.net (BastianK). Review: 7Artisans 28mm 5.6 M. https://phillipreeve.net/blog/review-7artisans-28mm-5-6-m/