| 摘要 |
The invention relates to a compact, high-performance yet wide-field real image type zoom finder comprising a positive objective optical system Ob and a positive eyepiece optical system Ep and further including an image-inverting means for erecting an real image formed by the objective optical system. The objective optical system Ob comprises a plurality of moving groups G2 and G3, and the eyepiece optical system Ep comprises positive reflecting surfaces, at least one of which is defined by a rotationally asymmetric surface, and satisfies conditions 1.25<DEP/fOC<2.0 AND 0.5<LOC/fOC<1.3 WHERE DEP is the distance as measured along an axial chief ray from a final surface to an eye point of the eyepiece optical system, fOC is the focal length of the eyepiece optical system, and lOC is the length as calculated on an air basis and measured along an axial chief ray from an intermediate image-formation plane to the final surface of the eyepiece optical system.
|
