| 摘要 |
PURPOSE:To obtain a titled lens of >=60 deg. view angle, about F2.8 of which the overall length from an image face is about 1.1 times as long a composite focal distance of a lens system, by satisfying prescribed conditions, in a behind-the aperture lens constituted of 4 pieces in 3 groups or 5 pieces in 4 groups. CONSTITUTION:A titled lens is constituted of the first converging lens group being a cemented lens of a negative meniscus lens (the first lens) and a positive meniscus lens (the second lens), and the second converging lens group consisting of a negative biconcave lens (the third lens) and one or two positive lenses, in order from an object side. Also, when fIIa denotes a focal distance of the nearest face of the second converging lens group to the object side, and fII2 denotes a focal distance of the nearest face to the image side respectively, prescribed conditions (1)-(6) are satisfied. |
