Mamiya-Sekor C 50mm F/4.5

Wide-angle prime lens • Film era • Discontinued

  • Announced:
  • · 1974
  • Production status:
  • ● Discontinued
  • Country of design:
  • · Japan
  • Original name:
  • · MAMIYA-SEKOR C 1:4.5 f=50mm
  • Class:
  • · Slow 6x7 medium-format wide-angle prime lens
  • · Professional model (Top class)
  • System:
  • · Mamiya RB67 (1970)

Abbreviations

C Multi-layer anti-reflection coating is applied to the surfaces of lens elements. This anti-reflection coating increases light transmission, eliminates flare and ghosting, and maintains color consistence among all lens models.

Model history (2)

■Mamiya-Sekor 50mm F/4.5A11 - 80.28m⌀77 1970 ●
■Mamiya-Sekor C 50mm F/4.5A11 - 80.28m⌀77 1974 ●

Specification

Optical design:
Medium format 6x7
50mm
F/4.5
11 elements in 8 groups
Floating element system
Mamiya RB67 [111mm]
84°
Diaphragm mechanism:
Diaphragm type:
Automatic
Aperture control:
Aperture ring (Manual settings only)
Built-in leaf shutter:
Type:
Mechanical Seiko #1
Range of shutter speeds:
1 - 1/400 + T
Self-timer (V):
-
Shutter speed control:
Shutter speed ring
Flash sync mode:
M & X sync
Flash sync terminal:
Yes
Focusing:
0.279m
0.05m
1:1.14
Focusing modes:
Manual focus only
Manual focus control:
None; focusing from the camera
Physical characteristics:
780g
⌀94×73mm
Accessories:
Screw-type 77mm
80mm - Clamp-on square
Not available

Sources of data

  • Interchangeable lenses for Mamiya RB67 instructions.
  • Mamiya interchangeable lenses for Mamiya RB67 Professional instructions.
  • The photograph. Mamiya RB67 Pro S booklet.
  • Mamiya RB67 Pro S price list by Bell & Howell (1975).
  • Mamiya RB67 Pro S booklet (1977).
  • Mamiya RB67 Pro-S booklet.
  • Mamiya RB67 Pro-S instructions.
  • Mamiya RB67 Pro-SD system accessories chart.
  • Mamiya RB67 Pro-SD booklet (2 ED., PUB. 2112).
  • Mamiya medium format cameras booklet.
  • Mamiya medium format cameras booklet (PUB. 9012).
  • Mamiya medium format cameras booklet (PUB. 9022).
  • Mamiya RB67 Pro-SD booklet (13 ED., PUB. 2112).

Manufacturer description #1

The 50mm f/4.5 lens is presently the most representative of the wide-angle lenses. its picture angle corresponds to the 24mm and 28mm lenses for the 35mm camera. Its range of applications is extremely wide and its floating lens element system gives it superb performance for subjects close to the lens. It was the first medium-format lens of its type to use the floating element system.

Manufacturer description #2

The 50mm f/4.5 is an ultra-wide lens exhibiting minimal distortion and extreme depth of field, dramatically linking foreground and background subject matter. Applications include landscape, architecture and photojournalism.

Mamiya-Sekor C series

The second generation of lenses designed for Mamiya RB67 series medium format 6x7 SLR cameras. Introduced with the Mamiya RB67 Professional S in 1974.

  • New barrel design;
  • Mechanical Seiko #1 leaf shutter;
  • Fully synchronized for M- and X-settings so that you can work with flash at all shutter speeds;
  • Fully automatic diaphragm;
  • Multi-layer anti-reflection coating;
  • Standardized 77mm filter thread mount for optimized handling with accessories (except the 37/4.5 fisheye and 500/8 lenses).

Other wide-angle prime lenses in the Mamiya RB67 system

■Mamiya RB67 mount (6)
Mamiya-Sekor 50mm F/4.5A11 - 80.28m⌀77 1970 ●
Mamiya-Sekor 65mm F/4.5A8 - 8⌀77 1970 ●
Mamiya-Sekor C 65mm F/4.5A8 - 7⌀77 1974 ●
Mamiya-Sekor NB 65mm F/4.5A8 - 8⌀77 1974 ●
Mamiya K/L 65mm F/4 LA9 - 80.35m⌀77 1990 ●
Mamiya K/L 75mm F/3.5 LA9 - 70.38m⌀77 1990 ●

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