Zeiss 10×50 “Jahrhundertglas”

Specifications:

Objective diameter:  50 mm
Magnification:  10x
Exit pupil: 5 mm
Usable eye relief (measured from rim of bakelit eyecup): 5 mm
IPD: 54  – 76 mm
RFOV:  7.4  degrees = 130 m
Minimum focus distance (measured): 7.3 m
Focus type: CF (direction of rotation from close to infinity: > clockwise)
Degrees of rotation of focus wheel from 7.3 m to infinity (measured): 200 degrees
Range of diopter adjustment (estimate): +/- 3 dpt*
Excess travel of focus wheel beyond infinity position (estimate): 7 dpt*
Prism system:  Porro I
Waterproof: splashproof
Weight (measured, with eyepiece cover and strap): 1‘038 g
Made in: Germany
*range of diopter adjustment not affected by position of focus wheel

Remarks:

First introduced in 1957, Zeiss (Oberkochen, West Germany) soon named this 10×50 classic porro binocular “Jahrhundertglas” because of its rare combination of compact size and very wide field of view, compared to other 10×50 instruments. The sample presented here was made around 1970 (serial number: 817169). Tele-objectives with a wide air space gave it the wide field of view, while “Astroplanar” five lens eyepieces allowed for an amazingly good edge sharpness.