| 摘要 |
PROBLEM TO BE SOLVED: To provide a finder optical system having large observation magnification, capable of observing a large finder image, and capable of securing an eye relief for a sufficiently long period.SOLUTION: A finder optical system includes an erect image forming member that forms an object image formed on a predetermined surface by a photographic lens into an erect image, and ocular lenses for observing an object through the erect image forming member. The ocular lenses include in order from an object side to an observation side a first lens group having a negative refractive power, a second lens group having a positive refractive power for performing diopter adjustment, and a third lens group having a negative refractive power. The finder optical system appropriately sets a focal distance f of the entire system, a focal distance f1 of the first lens group, a focal distance f3 of the third lens group, respectively when the ocular lenses have -1 diopter. |
