Mamiya APO-Sekor Z 350mm f/5.6 (RZ67)

The APO-Sekor Z 350mm f/5.6 is the middle lens of the four apochromats Mamiya built for the RZ67, 170 mm in 35 mm terms by Mamiya’s conversion, sitting between the 250 and the 500 f/6. Mamiya’s Mamiya-Sekor Z lens sheet and its APO Sekor Z brochure both list it at 7 elements in 6 groups, 15°, f/5.6 to f/45, 0.13× at full bellows extension, a 77 mm screw-in filter and hood, 97 × 192 mm and 1455 g. The Pro IID brochure of 2004 gives a closest focus of 3.42 m from the film plane, which Japanese Wikipedia carries as 3.423 m. The brochure describes ultra-low dispersion glass and a correction that extends into the infrared, so that no focus shift is needed between colour, black and white and infrared film, and adds one practical note: when reading close-up exposure compensation off the body’s focal-length scale, the 350 is read between the 180 and 250 marks.

There is one version. The 1982 RZ67 manual has no 350; the APO brochure, which says its list includes lenses still coming, has it beside the 210, 250 and 500 f/6; the 2004 Pro IID brochure still lists it while the older 360mm f/6 has gone. Zach van Rijn dates the RZ APO series to 1988 and the RB67 versions to 1990, the only year found, so it is flagged. The RB67’s APO KL 350mm f/5.6 has the same construction and weight class but carries its own shutter-speed ring and is a different lens with its own page; Mamiya’s Lens Holder manual covers all four of the RZ 360, RZ 350 APO, RB 360 and RB 350 APO, with separate mounting positions for the two bodies.

Reviews are thin. Pierre-Gilles Lucain, whose Emulsive guide is the one review found, has not used the 350 and lists it from Mamiya’s figures, noting the fraction of a stop over the 360 and repeating his general view that APO correction pays in colour and hardly at all in black and white. A member of the Flickr RZ67 group, having found the 360 underwhelming, called the much newer 350 APO far better and by then relatively cheap. Van Rijn calls the APO lenses some of the finest medium-format glass made and, in the same breath, reports that all but the 500 suffer badly from balsam separation, the 350 having one cemented doublet; he has repaired 210 and 250 K/L lenses himself and warns that mint-looking examples can be unusable.

Buying checks start with that doublet: hold the lens to a bright light and look for the oily rings, edge crazing or a rainbow sheen of separating cement, which shows more in the APO series than in the plain Z lenses. Then the RZ system’s usual points. The Seiko #1 electronic leaf shutter fires only with a working 6 V battery in the body; without one it gives a mechanical 1/400 and nothing else. The lens comes off only when the body’s lever has cocked it with the mirror down, so a lens that will not release is usually a cocking-state matter. Run the shutter at 8 s and 1/400 and watch the blades, work the depth-of-field preview and T levers, and check the rear contacts. The 350 is 192 mm long and Mamiya’s Lens Holder for the 350 and 360 cradles its narrower front barrel; the holder’s own tripod socket is where a long exposure on a tripod belongs, and Mamiya’s manual says not to carry the combination by the tripod. Lucain’s list of lenses that take the 1.4× teleconverter omits the 350.

What could not be sourced from a Mamiya document: the introduction year, the number of aperture blades, the coating, a list price in any currency and the year production ended. No designer is named anywhere.