Marine binoculars outdoor binoculars underwater binoculars with internal rangefinder and illuminated compass area of use watersports nature outdoor sports magnification 7 x lens diameter 50 mm prism system porro suitable for intermediate expert exit pupil diameter 714 mm min focus distance 106 m angle of view 67 field of view in 1000 m 117 m twilight factor 187 relative brightness 50 98 focussing system individual focus viewing straight binoc