摘要 |
An electronic imaging apparatus has a zoom optical system in which the most object-side lens unit A includes one biconcave-shaped negative lens component, each of air-contact-surfaces of which is configured as an aspherical surface, and when the magnification of the zoom optical system is changed in the range from a wide-angle position to a telephoto position, the lens unit A is moved back and forth along the optical axis in such a way that the lens unit A is initially moved toward the image side, and an electronic imaging unit that has an electronic image sensor so that image data picked up by the electronic image sensor are electrically processed and can be output as image data whose format is changed. In this case, in nearly infinite object point focusing, the zoom optical system satisfies the following condition: <?in-line-formulae description="In-line Formulae" end="lead"?>0.7<y<SUB>07</SUB>/(fw.tan omega<SUB>07w</SUB>)<0.94<?in-line-formulae description="In-line Formulae" end="tail"?> where y<SUB>07 </SUB>is expressed by y<SUB>07</SUB>=0.7y<SUB>10 </SUB>when y<SUB>10 </SUB>denotes a distance from the center to a point farthest from the center within an effective imaging surface of the electronic image sensor, omega<SUB>07w </SUB>is an angle made by a direction of an object point corresponding to an image point, connecting the center of the imaging surface at the wide-angle position and the position of the image height y<SUB>07</SUB>, with the optical axis, and fw is the focal length of the entire system of the zoom optical system at the wide-angle position.
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