| 摘要 |
PURPOSE:To obtain a high-performance, compact zoom lens for a 35mm. single- lens reflex camera which covers a 35-80mm. focal-length range, by composing the zoom lens system of two front and rear groups which have negative refracting power and positive refracting power from an object side. CONSTITUTION:A front group consists of three-four lenses including >=1 positive lens and >=1 negative lens and a positive meniscus lens at the closest position to an image, and a rear group consists of six lenses-a positive, a positive meniscus, a negative, a negative meniscus, and a positive lens-from an object side. Further, inequalities (1)-(3) hold. |
