Carl Zeiss Jena Jenoptem 8×30

Specifications:

Objective diameter:  30 mm
Magnification:  8 x
Exit pupil: 3.75 mm
Eye relief (acc. to spec): 18 mm
Usable eye relief (measured from rim of unfoldable eyecup): 5.5 mm
IPD: 49  – 73 mm
RFOV:  8.6  degrees = 150 m
AFOV (measured, rounded): 65.5 degrees
Minimum focus distance (measured): 2.5 m
Focus type: CF (direction of rotation from close to infinity: > clockwise)
Degrees of rotation of focus wheel from 3 m to infinity (measured): 265 degrees
Range of diopter adjustment (estimate): +/- 5 dpt*
Excess travel of focus wheel beyond infinity position (estimate): 4 dpt*
Prism system:  Porro I
Waterproof: splashproof (?)
Weight (measured, with eyepiece cover and strap): 550 g
Made in: DDR (East Germany)
*range of diopter adjustment not affected by position of focus wheel

Remarks:

The Jenoptem 8×30 was in production for many years; for some time, another name, ‘Deltrintem’, was also used for this central focus model (whereas the individual focus model was called ‘Deltrentis’, see separate post https://binocular.ch/carl-zeiss-jena-deltrentis-8×30/). This particular sample was produced in 1988, was probably exported to West Germany before the re-unification, but never sold to a consumer, and was found brand new in 2013 in an optics store in Stuttgart, Germany. Light weight, good central sharpness, mediocre edge sharpness, a relatively bright image and relatively well controlled CA are the characteristics of this instrument. A special treat: the IPD goes down to a narrow 49mm, so the Jenoptem can also be used by children.