The glasses are produced with various colour cases and may have the magnification from 2.3 to 4 times. The glasses with magnification 2.5 times ensure clear image of the distant objects from 1 meter to infinity and with magnification 4 times - from 2 meters to infinity.
Opera glasses have central focusing system.
24 Limit of resolution, ang. 25 Limit of resolution, ang. 36 Limit of resolution, ang.