Nedis 8x21 Binoculars

The magnification number indicates how many time an object is magnified by the lens. The larger the number the higher the magnification. For a binocular with magnification 7 or 10 is most useful. When the number is higher it will result in less stability of the image.

The darker the environment the larger your pupil will become. When your pupil becomes larger than the exit pupil diameter visibility will be less clear. A human eye pupil diameter can change from 2 mm up until 7 mm. So in case you expect use a binocular often in the dark then a high exit pupil diameter will be important. 7 mm can even be used at night. 5 mm is suitable for dusk and dawn. Under 5 mm is more suitable in day-time.