Data sheet: Mamiya E 50 mm f/2 (Z/E mount)

Pekka Buttler, 01/2025

Pictured: Mamiya-Sekor E 50 mm f/2

Specifications

The table below summarizes the lens’ key specifications (measurements based on pictured, last version of the lens):

Brand:Mamiya-SekorLens nameE 1:2 f=50mm
Focal length(s)150 mmAngle-of-view247°
Maximum Aperturef/2In Production1980-1982
Lens mountMamiya Z/ESubfamily (if applicable)––
Length333,3 mmDiameter461,9 mm
Filter ring diameter49 mmWeight142 grams
Lens element count6Lens group count4
Aperture blades (S/R/C)56 SFocus throw200 °
Minimum focusing distance45 cmsMaximum magnification1:6,9
Has manual aperture ringNOHas Manual focus ringYES
Aperture mechanism typeelectronic/mechanical 6Aperture click stops 72•2.8•4•5.6•8•11•16

Further notes:

• In 1980 Mamiya introduced the Z line of cameras and lenses. On its introduction, it was introduced with two 50 mm primes – a 50 mm f/1.7 lens and this 50 mm f/2 lens. This lens was clearly designated to be the entry-level lens. A 50 mm f/1.4 lens was introduced in 1981.
• With its 49 mm filter thread and super-compact size, this lens is a typical example of late manual era nifty fifty.
• This lens was replaced only 2 years later by the “Mamiya-Sekor E 50 mm 1:2 S” (the letter S was in red).
• As a quirk that was typical for the Mamiya Z system, the lens does have an aperture ring, but that ring has no function on the lens itself (Mamiya Z lenses aperture rings communicated the chosen aperture to the camera, which in turn did the closing down). This has implications on adaptability (read more below).

Versions and variants

Besides its successor (the Mamiya Sekor E 50 mm 1:2 S), there was only ever one version of the Mamiya-Sekor E 50 mm f/2. Importantly, the “Mamiya-Sekor E 1:2 50 mm” (this lens) and its successor (the “Mamiya-Sekor E 50 mm 1:2 S”) have little in common beside the mainline specifications as one was a real Mamiya lens and the other was manufactured by some Japanese lens manufacturer (likely Osawa) and rebranded as a Mamiya lens.

History of Mamiya Z/E lenses

Please see the JAPB article on all (7) Mamiya SLR lens mounts to understand the role of the Mamiya Z/E mount.

Adapting

n.B! The following applies to all Mamiya Z/E mount lenses.

This lens cannot be used natively on any current SLR or dSLRs. To use it in its native environment, you will need a Mamiya Z/E-mount film body – a ZE, ZE-2, ZE-X or ZM. While the Mamiya Z/E system remained in production for only 4 years (and was not a mega-hit), these bodies are relatively easy to find.

While the lens sports electronic contacts, these are not needed to facilitate critical functionality. However, as the aperture ring of Mamiya Z/E lenses is a dummy ring (it does not manipulate the lens’ aperture in any way – it instead communicates the aperture to the camera body, which in turn manipulates the lens’ aperture lever), adjusting aperture is a function that has to be taken care of by the adapter.

Therefore, should you aim to adapt this lens to a mirrorless camera you will need an adapter that facilitates adjusting the lens’ aperture. Luckily, every Mamiya Z/E adapter I’ve seen does offer such a functionality. However, due toMamiya Z/E lenses not being among the most numerously manufactured, special adapters (helicoid adapters, tilt/shift adapter and speed boosters) are currently unavailable.

Using Mamiya Z/E lenses on dSLRs is also possible. However, due to that the, difference in flange focal distances between the Mamiya Z/E lens and the dSLR mount (between +1,5 mm and negative 1 mm) invariably does not allow sufficient space for an adapter that allows aperture modification, these adapters are always adapters with added optics to achieve infinity focus.

Footnotes

  1. Focal length is (unless stated otherwise) given in absolute terms, and not in Full-frame equivalent. For an understanding of whether the lens is wide/tele, see ‘Angle-of-view’. ↩︎
  2. Picture angle is given in degrees (based on manufacturers’ specs) and concerns the diagonal picture angle. Rule of thumb:
    > 90 ° ==> Ultra-wide-angle
    70–90 ° ==> Wide-angle
    50–70 ° ==> Moderate wide-angle
    40–50 ° ==> ‘Standard’ or ‘normal’ lens
    20–40 ° ==> Short tele lens
    10-20 ° ==> Tele lens
    5-10 ° ==> Long tele lens
    < 5 ° ==> Ultra-tele lens ↩︎
  3. Length is given from the mount flange to the front of lens at infinity. ↩︎
  4. Diameter excludes protrusions such as rabbit ears or stop-down levers. ↩︎
  5. S=straight; R=rounded; C=(almost)circular at all apertures. ↩︎
  6. The lens communicates the selected aperture electronically, but the lens is closed down mechanically. ↩︎
  7. Numbers equal aperture values on aperture ring; • intermediate click; – no intermediate click. ↩︎

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