OPTICAL SIGHT WITH ALTERNATING MAGNIFICATION Russian patent published in 2006 - IPC G02B23/14 F41G1/38 G02B9/04 

FIELD: optical sights and telescopes operating in the visible range of radiation spectrum.

SUBSTANCE: the sight with an alternating magnification has a three-lens objective, sight reticule, field component, two-component panchromatic erecting system, range-finding reticule, collective lens and an ocular installed in succession in the direction of rays. The objective has cemented first two lenses-biconvex and negative ones, and the third lens-singular positive meniscus turned with the convexity to the object. The biconvex and singular lenses are made of the same material with dispersion factor ν_D, which corresponds to condition 50≤ν_D≤70 that is more than the dispersion factor of the material of the negative lens by 2 to 2.5 times. The relations given in the patent claim are fulfilled between the focal distances of the cemented lens, objective, biconvex lens, negative lens and singular lens.

EFFECT: improved accuracy characteristics, and namely, reduced errors of the sight angle.

1 dwg, 2 tbl