Zoom binoculars area of use watersports travel magnification 7 x lens diameter 50 mm zoom factor 5 times prism system porro exit pupil diameter 714 mm min focus distance 8 m angle of view 38 field of view in 1000 m 66 m twilight factor 187 relative brightness 50 98 diopter correction 3 0 dpt viewing binocular straight weight 961 g special features rubber armouring