Mamiya APO-Sekor Z 500mm f/6 (RZ67)

Mamiya · Mamiya RZ67 · 1988

single source, unconfirmed

Also known as: Mamiya APO-Sekor Z 500mm f/6 · Mamiya APO Sekor Z 500mm F6 · Mamiya Sekor Z 500mm f/6 APO · Mamiya 500mm f/6 APO · Mamiya RZ67 500mm f/6 · Mamiya RZ 500mm 6 APO · APO Z500mm f/6 · マミヤ APO セコール Z 500mm F6 · アポセコールZ 500mm F6 · マミヤ RZ67 500mm F6

Variants & identification

Variant Mount Years Serial ranges Production
Mamiya APO-Sekor Z 500mm f/6 (one version) Mamiya RZ67 1988
  1. Construction, angle of view, minimum aperture, magnification, weight and dimensions are from Mamiya's Mamiya-Sekor Z Interchangeable Lenses sheet and its APO Sekor Z brochure, which agree. The sheet's minimum-focus column is measured from the lens front rim with the bellows fully extended (46 mm), not from the film plane; the 6.49 m in the spec fields is the Pro IID brochure's figure, which Japanese Wikipedia gives as 6.493 m. The sheet's dimension column is read here as diameter × length; the Pro IID brochure prints 278.5 × 108 mm. The sheet and the APO brochure call the hood slip-on; the Pro IID brochure's table prints screw-in, and its accessory list still names the ø108 No. 1 slip-on hood for the 500mm.
  2. The 1988 introduction comes from Zach van Rijn's blog alone; Mamiya's APO brochure is undated and says only that the list includes lenses coming soon: single source. Van Rijn is also the one source for the absence of cemented groups, which the seven-element, seven-group construction in Mamiya's table is consistent with.
  3. This is the only 500mm APO Mamiya made for the RZ67. The plain Z500mm f/8 W is a different, older design with its own page; no source consulted knows a 500mm f/8 with the APO designation.
  4. The Pro IID brochure gives 238 mm as the 35 mm equivalent where the earlier sheet gives 242 mm; both are Mamiya's own rounding of the same lens. No aperture-blade count, coating description or list price in any currency was found in a Mamiya document.
How to tell them apart (expand)
  • RZ bayonet with electrical contacts and a Seiko #1 electronic leaf shutter; no shutter-speed ring on the lens. A 500mm APO with its own speed ring is the RB67's APO KL 500mm f/6, a different lens
  • Minimum aperture f/45; 105 mm filter and the ø108 No. 1 slip-on hood; 280 mm long, 2315 g
  • Mamiya lists a dedicated Lens Holder for the 500mm lens; the brochure rules out the auto extension tubes and the 1.4× teleconverter on this lens

Mamiya APO-Sekor Z 500mm f/6 (one version):

  • APO on the name ring; a 105 mm front with a slip-on hood; no W or other suffix was ever applied to this lens
  • Mamiya-Sekor Z lens sheet and APO brochure: 7 elements in 7 groups, 10°, f/45, 0.09× at full bellows extension (6064 mm from the front rim), 242 mm equivalent, 108 × 280 mm, 2315 g¹
  • Pro IID brochure (2004): 6.49 m closest focus, 278.5 × 108 mm, 2315 g, 238 mm equivalent; Japanese Wikipedia: 7群7枚, 6.493 m, φ105 mm
  • 19 mm shorter and 355 g heavier than the plain Z500mm f/8 W; stops down to f/45 where the f/8 stops at f/32

Specifications

Formula
Apochromatic telephoto with ultra-low dispersion glass, 7 elements in 7 groups, no cemented surfaces (Mamiya lens sheet and APO brochure; van Rijn)
Construction
7 elements / 7 groups
Aperture range
f/6–f/45
Shutter
Seiko #1 electronic leaf shutter in the lens, 8s–1/400 plus B and T, set from the body dial; a mechanical 1/400 works without a battery
Min. focus
6.49 m
Dimensions
108 × 280 mm
Weight
2315 g
Filter
105 mm
Years manufactured
1988
Country
Japan

What reviewers say

Optical formula — Apochromatic telephoto with ultra-low dispersion glass, 7 elements in 7 groups, no cemented surfaces (Mamiya lens sheet and APO brochure; van Rijn)

History

The APO-Sekor Z 500mm f/6 is the longest and heaviest lens Mamiya made for the RZ67, 242 mm in 35 mm terms by Mamiya’s conversion, and the apochromatic replacement for the plain 500mm f/8. Mamiya’s Mamiya-Sekor Z lens sheet and its APO Sekor Z brochure both list it at 7 elements in 7 groups, 10°, f/6 to f/45, 0.09× at full bellows extension, a 105 mm filter, a slip-on hood, 108 × 280 mm and 2315 g. The Pro IID brochure of 2004 gives a closest focus of 6.49 m from the film plane, which Japanese Wikipedia carries as 6.493 m. The brochure describes ultra-low dispersion glass and a correction that extends into the infrared, so no focus shift is needed between film types, and adds two restrictions specific to this lens: neither the auto extension tubes nor the 1.4× teleconverter can be used on it.

There is one version. The 1982 RZ67 manual has only the 500mm f/8; the APO brochure, which says its list includes lenses still coming, has the f/6 beside the 210, 250 and 350; the 2004 Pro IID brochure lists the f/6 as the only 500. Zach van Rijn dates the RZ APO series to 1988 and the RB67 versions to 1990, the only year found, so it is flagged. Against the f/8 the APO is 19 mm shorter, 355 g heavier, most of a stop faster and stops down a stop further, to f/45. The RB67’s APO KL 500mm f/6 has the same construction but carries its own shutter-speed ring and is a different lens with its own page.

Reviews are thin. Pierre-Gilles Lucain, whose Emulsive guide is the one review found, owns the f/8 and not the APO; he describes the f/6 as the same reach with better colour correction and a higher price, and holds that APO correction pays in colour and hardly at all in black and white. His account of the f/8, huge and cumbersome but incredibly sharp and in need of the lens support, applies at least as much to a lens 355 g heavier. Van Rijn calls the APO lenses some of the finest medium-format glass made and singles this one out as the exception to the series’ balsam-separation problem: with no cemented groups there is nothing to separate, which fits the seven-element, seven-group construction in Mamiya’s table.

Buying checks are the RZ system’s, with the mass added. 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. Ask whether Mamiya’s Lens Holder for the 500mm and the ø108 slip-on hood come with it, because both are separate accessories and 2.3 kg should not hang from the bayonet on a tripod. Haze and fungus are the glass checks here rather than separation.

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.

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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 APO-Sekor Z 500mm f/6 (RZ67)? We'd love to feature it (with credit).

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