Compact binoculars underwater binoculars area of use travel watersports magnification 8 x lens diameter 24 mm prism system porro exit pupil diameter 3 mm min focus distance 2 m angle of view 66 field of view in 1000 m 114 m twilight factor 139 relative brightness 9 focussing system central focus viewing straight binocular coating high contrast weight 830 g included in delivery pouch eyepiece caps shoulder strap special features for specta