Astronomy binoculars area of use astronomy magnification 15 x lens diameter 70 mm prism system porro exit pupil diameter 467 mm min focus distance 131 m angle of view 44 field of view in 1000 m 77 m twilight factor 324 relative brightness 21 81 viewing binocular weight 1 361 g included in delivery pouch tripod adapter outdoor function waterproof prismenglas bak 4