Outdoor binoculars underwater binoculars area of use nature outdoor sports travel magnification 10 x lens diameter 50 mm prism system roof suitable for beginner intermediate exit pupil diameter 5 mm min focus distance 35 m angle of view 5 field of view in 1000 m 87 m twilight factor 224 relative brightness 25 diopter correction 3 0 dpt focussing system central focus viewing straight binocular coating multi coated weight 840 g eye re