| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a photographic optical system capable of lessening high intensity of light, such as sunlight at outside of a screen to which a diffractive optical element is exposed, capable of satisfactorily correcting color aberrations, while reducing flare ghosts due to the diffractive optical element to the utmost and, resultantly having high optical performance, and to provide imaging equipment that has the photographic optical system. <P>SOLUTION: In the photographic optical system which comprises a first lens group of positive refractive power, an aperture diaphragm and a second lens group of positive or negative refractive power, in this order starting from an object side to an image side, the diffractive optical element is disposed on a lens surface which is located closer to the object side, than to the opening aperture and satisfies the condition 0.1<ϕdo/ϕf<0.7, where a light ray effective diameter of a positive lens on a side nearest the object of the first lens group isϕf and the light ray effective diameter on an arbitrary lens surface isϕdo, and a material satisfying the condition 0.5<θgF<0.6, 75<νd is used for at least a lens, satisfying the condition 0.2<ϕdo/ϕai<1.5, where the light ray effective diameter of each lens constituting the photographic optical system isϕai. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
