Mamiya Sekor AF 28mm f/4.5 D Aspherical
Mamiya · Mamiya 645 AF · 2007
Also known as: Mamiya Sekor AF 28mm f/4.5 D Aspherical · Mamiya 28mm f4.5 D Aspherical · Mamiya AF 28mm F4.5 D · Mamiya 645 AF 28mm f/4.5 · Mamiya 645AFD 28mm · Mamiya Sekor D 28mm f/4.5 · Phase One 28mm f/4.5 AF Aspherical · Phase One AF 28mm f4.5 · マミヤ セコール AF 28mm F4.5 D Aspherical · マミヤ AF 28mm F4.5 D · マミヤ645AF 28mm F4.5
Variants & identification
| Variant | Mount | Years | Serial ranges | Production |
|---|---|---|---|---|
| Mamiya Sekor AF 28mm f/4.5 D Aspherical | Mamiya 645 AF | 2007 | — | — |
- Optical construction (14 elements in 10 groups with aspherical surfaces), the f/4.5–32 aperture range, 35 cm closest focus and 0.15× magnification are from dc.watch's 22 March 2007 announcement; the Japanese Wikipedia product list and Kamerastore repeat 14 in 10 and 35 cm. The 102° angle of view, 136 mm length, 90 mm diameter and 886 g are from Mamiya Leaf's lens page (archived 2014), which lists the leaf-shutter LS version with the same figures; the English Wikipedia table gives 885 g for this lens and 886 g for the LS.
- Prices: ¥672,000 at the June 2007 release (dc.watch, 27 July 2007) and the same figure on Mamiya's November 2009 list of prices being replaced by open pricing; Japanese prices of this period are quoted with tax. No dollar list price was found in a source consulted.
- The Mamiya Sekor AF 28mm f/4.5 LS D Aspherical is a later leaf-shutter version for the 645DF bodies with the same optics (Mamiya Leaf; English Wikipedia); it is a different lens and not on this page.
- The aperture blade count and a discontinuation date are not given by any source consulted.
How to tell them apart
- The widest lens of the Mamiya 645 AF line and the only 28mm; name ring reads Sekor AF 28mm f/4.5 D Aspherical, with a built-in petal hood and no front filter thread
- Gelatin sheet filter in a frame at the rear mount (dc.watch; Mamiya Leaf); any 28mm with a leaf shutter and an LS marking is the 645DF-era LS D version
- Nothing in the manual-focus M645 line is a 28mm, so there is no manual-focus look-alike; the Mamiya 7's 43mm and the RB/RZ 37mm fisheyes are different systems
Mamiya Sekor AF 28mm f/4.5 D Aspherical:
- Sekor AF 28mm f/4.5 D Aspherical on the name ring; built-in petal hood and no front filter thread, the filter being a gelatin sheet in a frame at the rear mount (dc.watch, March 2007; Mamiya Leaf lens page)
- Autofocus and manual focus switched by sliding the distance ring fore and aft, as on Mamiya's telephoto and zoom lenses (dc.watch, March 2007)
- Marked 17mm equivalent on 645 film and 20mm on the Mamiya ZD; dc.watch's 2007 report calls it the widest lens of the line
- Mamiya Sekor AF 28mm f/4.5 D Aspherical: The only version. Announced on 22 March 2007 with the Sekor Zoom AF 75-150mm f/4.5 D as the first two lenses of the Mamiya Sekor D series for the Mamiya ZD digital SLR and the 645AFD II film body, and released in June 2007 at ¥672,000 (dc.watch, 22 March and 27 July 2007). Mamiya's 27 July 2007 notice says a ZD or an early 645AFD needs a free software update at a service centre to show the aperture with this lens, that the 645AFD II is already compatible, and that an original 645AF must be converted to AFD specification (¥18,900 for the full conversion, ¥7,350 for the software update) before it can use the lens. From 16 November 2009 Mamiya moved the Sekor D lenses to open pricing, listing this one at ¥672,000 until then and naming the Mamiya ZD, 645AFD III and 645DF as the bodies that take the series (dc.watch, 4 November 2009). Phase One sold the same lens as the Phase One 28mm f/4.5 AF Aspherical.
Specifications
- Formula
- 14 elements in 10 groups including aspherical elements (dc.watch, 22 March 2007; Japanese Wikipedia product list)
- Construction
- 14 elements / 10 groups
- Aperture range
- f/4.5–f/32
- Min. focus
- 0.35 m
- Dimensions
- 90 × 136 mm
- Weight
- 886 g
- Filter
- Gelatin sheet filter in a frame at the rear mount; no front thread
- Years manufactured
- 2007
- Country
- Japan
- Coating
- Multicoated; Mamiya America's lens brochure says every element is coated with Mamiya's proprietary multi-coating process, and Damien Demolder's 2015 field test says the D-era lenses carry coatings and an exit light path reworked for digital sensors (dpreview, cited on the AF 80mm page)
- Original price
- ¥672,000 (2007, tax included) (today ¥763,000)
What reviewers say
No reviews aggregated yet — this family is still in the research queue. Written one? We'd love to index it.
History
The Sekor AF 28mm f/4.5 D Aspherical is the widest lens Mamiya made for the 645 AF bayonet, a 17mm equivalent on 6×4.5 film and a 20mm equivalent on the 48 × 36 mm sensor of the Mamiya ZD. It was announced on 22 March 2007 together with the Sekor Zoom AF 75-150mm f/4.5 D as the first two members of the Mamiya Sekor D series, lenses that Mamiya Digital Imaging presented as designed for its medium-format digital SLR and usable on the 645AFD II film body as well, and it reached the shops in June 2007 at ¥672,000. The design is 14 elements in 10 groups with aspherical surfaces, f/4.5 to f/32, focusing to 35 cm for 0.15×, with a built-in petal hood and no front thread: filters are gelatin sheets in a frame at the rear mount. Mamiya Leaf’s later page gives 102° angle of view, 136 mm length, 90 mm diameter and 886 g, and Wikipedia’s table 885 g.
Compatibility was the complication of the early D lenses. Mamiya’s notice of July 2007 says a ZD or an early 645AFD fails to display the aperture with this lens until a free software update is applied at a service centre, that the 645AFD II needed nothing, and that an original 645AF has to be converted to AFD specification, at ¥18,900, before it can use the lens at all. The 645AFD III of April 2008 took the D lenses from the start: Mamiya’s own specification page quotes its metering range with the AF 80mm f/2.8 D, and the November 2009 price notice lists the Mamiya ZD, the 645AFD III and the digital-only 645DF as the bodies for the Sekor D series. The lens stayed in the line through the Phase One and Mamiya Leaf years, when a leaf-shutter LS D version with the same optics joined it for the 645DF; Phase One sold the focal-plane version under its own name.
No independent review of the lens was found in the sources consulted; retailer copy and Mamiya Leaf’s page describe edge-to-edge sharpness and the aspherical design, which are the maker’s claims. The 2007 price and the rear sheet-filter arrangement explain why examples are scarce on the used market.
When buying, check the rear electronic contacts, that the distance ring slides cleanly between its autofocus and manual positions, that the body reports the lens and its aperture (an unconverted 645AF or an un-updated early AFD will not), and that the rear filter frame is present. An LS marking means the 645DF-era leaf-shutter lens, which is a different page.
What remains open: the aperture blade count, a dollar list price, the production years, and whether Mamiya published a data sheet with its own dimensions for the focal-plane version.
This history is AI-written, from the sources listed at the foot of the page. Where the record is silent it says so rather than filling the gap — but no human wrote these sentences.
Example photos
Sample photo wanted — shot with a Mamiya Sekor AF 28mm f/4.5 D Aspherical? We'd love to feature it (with credit).
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