Marine binoculars area of use bird watching watersports magnification 7 x lens diameter 50 mm prism system porro exit pupil diameter 714 mm min focus distance 7 m angle of view 71 field of view in 1000 m 124 m twilight factor 187 relative brightness 50 98 diopter correction 4 6 dpt focussing system individual focus viewing straight binocular coating fully coated weight 1 010 g special features for spectacle wearers rubber armouring o