| 摘要 |
An improved Gauss type lens system having a relatively large aperture ratio is provided. The lens system comprises seven components between object and image as follows; a first positive meniscus lens element, a second positive meniscus lens element, a third negative meniscus lens element, a fourth meniscus shaped doublet, a fifth positive meniscus lens element, and a sixth positive lens element. The entire lens system is capable of providing a relative aperture of F No. 1.2, an angle of view of 50 DEG and a back focus at least 0.7 times the overall focal length of the lens system.
|
