OPTICAL SYSTEM AND ENDOSCOPE

PROBLEM TO BE SOLVED: To provide an optical system by which occurrence of cloudiness of a lens, dew condensation, image inferiority or the like associated with change of environment such as temperature change can be prevented and to provide an endoscope equipped with the optical system. SOLUTION: This optical system is constituted of a plurality of optical parts, air of ≤0°C dew point in atmospheric pressure is enclosed therein and further moisture content in the air at atmospheric pressure and 20°C is regulated to be ≤4.85 g/m3. The optical parts are equipped with a member which does not need light transmissivity and a coating film containing a moisture absorbent and a dark-colored coloring agent is formed on at least a part of a member surface. The optical parts are equipped with a lens, and the lens is an objective lens and is a lens for the endoscope. COPYRIGHT: (C)2005,JPO&NCIPI