Hunting binoculars underwater binoculars outdoor binoculars area of use hunting digiscoping travel nature outdoor sports magnification 8 x lens diameter 42 mm prism system roof exit pupil diameter 525 mm min focus distance 13 m angle of view 74 field of view in 1000 m 130 m twilight factor 183 relative brightness 27 56 focussing system central focus viewing straight binocular weight 640 g eye relief 18 outdoor function waterproof