| 摘要 |
An extended depth-of-field (EDOF) surveillance imaging system (8) that has a lens system (10) with a total lens power &phgr;T and an amount of spherical aberration SA where 0.2λ≦̸SA≦̸2λ. The lens system includes first lens group (G1) and a second lens group (G2). The first lens group has first and second confronting meniscus lens elements (L1, L2) that have an overall optical power &phgr;1 such that |&phgr;1/&phgr;T|≦̸0.05. The second lens group has a doublet (D1) and a most imagewise positive lens element (L5). An aperture stop (AS) is arranged either between the first and second lens groups or within the second lens group. An image sensor (30) is arranged to receive the image and form therefrom a digitized electronic raw image. An image processor receives and digitally filters the digitized electronic raw image to form a digitized contrast-enhanced image. |
