OBSERVATION OPTICAL SYSTEM AND BINOCULARS HAVING THE SAME

摘要

To provide an observation optical system excellent in antireflection film characteristics by oblique light incidence at a specific wavelength band including a wavelength with strong visibility, while having low visibility of a ghost image by inverse incident light, allowing excellent and easy observation.SOLUTION: An observation optical system is for observing an object image, and includes an eyepiece optical system having a plurality of refraction optical elements. The eyepiece optical system has a positive lens G1 having a positive refractive power and a positive lens G2 having a positive refractive power. An antireflection film composed of a multilayer film is applied on an optical surface of at least one of the positive lens G1 and the positive lens G2. A reflective index R(R50), R(B50), R(R0), or R(B0) of a film constitution of the antireflection film is each set appropriately.SELECTED DRAWING: Figure 1