PROSTAFF 3S features an optical system created from lead-and-arsenic-free Eco-Glass. Multilayer coatings, which provide high light transmittance across the entire visible light spectrum, are applied for bright images. High-reflectivity silver-alloy mirror coating applied on the mirror surfaces of the prisms for a bright and clear view.
Long Eye Relief:
Nikon has manufactured the PROSTAFF 3S binoculars, as well as many other of its optics, with a high-eyepoint design for long eye relief without vignetting. This provides a clear field of view for everyone, even when the user is wearing eyeglasses.
PROSTAFF 3S has a rugged rubber-armoured coating to provide a non-slip grip, even in the wettest conditions.
Waterproof and Fogproof:
PROSTAFF 3S binoculars are Nitrogen filled and O-Ring sealed for complete waterproof and fogproof performance.
Type: Roof-prism central focusing type
Effective diameter of objective lens: 42mm
Real field of view: 7.2 degrees
Angular field of view (apparent): 53.4 degrees
Field of view at 1,000m/yd: 377 ft / 126 mm
Exit pupil: 5.3 mm
Relative brightness: 28.1
Eye relief: 0.8 in / 20.2 mm
Close focusing distance: 9.8 ft / 3.0 m
Length: 6.0 in / 152 mm
Width: 5.1 in / 130 mm
Thickness: 2.0 in / 52 mm
Weight: 19.9 oz / 565 g
Interpupillary distance adjustment: 2.2-2.8 in / 56-72 mm
Structure: Waterproof (Up to 1 metre for 10 minutes) and nitrogen gas filled