PENTAX AD 9×28 WP binoculars review
Introduction
The Pentar company kindly provided me with PENTAX AD 9×28 WP binoculars for review. These are compact binoculars with a unique 9×28 formula. The inverting system is made on the basis of prisms “with a roof” (roof). The manufacturer declares a multi-layer anti-reflection coating, a sealed nitrogen-filled construction, BAK4 prisms with a phase-correcting coating, a protective coating of the front lenses, a long eye relief, and a body made of light aluminum alloy.
Declared technical characteristics:
Type: binoculars with a central focusing mechanism and roof-prisms
Objective lens: 3 elements in 2 group
Eyepiece lens constructions: 5 elements in 4 groups
Magnification: 9x
Objective lens diameter: 28 mm
Linear field of view at 1000m: 98 m
Exit pupil: 3.1 mm
Eye relief: 18 mm
Diopter adjustment range: -/+ 4 D
Focusing distance:: from 3 m to infinity
Eyepiece Ring: Helicoid Type
Height: 44 mm
Width: 115 mm
Depth: 117 mm
Weight: 365 g
Waterproof and nitrogen-filled (JIS Class 6) to handle the most extreme weather conditions (submersible to 1m).
Prism coating: BaK4, phase coating
Lens coating: multilayer coating of all optical elements
Minimum focusing distance: 3 m
Angle of view actual: 5.6° (note: lettering on the case)
Twilight factor: 15.9
Interpupillary distance: 58 mm – 72 mm
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