| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain a finder optical system that has a high observation magnification while maintaining a sufficient distance from a focusing plate to an eyepiece optical system. <P>SOLUTION: The finder optical system for observing an object image formed on a specific surface by a photographic lens comprises, in order from a predetermined surface to an observing side, a condenser lens of positive refractive power, an image inverting member for forming an erect image, a first lens group of negative refractive power, a second lens group of positive refractive power, and a third lens group of positive or negative refractive power. If a principal-point interval between the condenser lens and the first lens group is H1, and an air conversion optical path length along an optical axis from the predetermined surface to the observing side face of the third lens group is d, the conditional expression, 0.50<H1/d<0.73, is satisfied. <P>COPYRIGHT: (C)2013,JPO&INPIT |
