| 摘要 |
PURPOSE:To obtain a lens which is good in axial and magnification chromatic aberration condition in a titled lens adapted for a middle telephoto lens of about 1:1 brightness, for example, a lens around 200mm. for 6X7 size or 150mm. for 6X 4.6size by adopting ultralow dispersion glass particularly effective for an ultratelephoto lens as an Elster type which is a middle telephoto type. CONSTITUTION:The specific 8 conditions are satisfied in a lens of the 4-group 4-element constitution wherein the 1st lens, successively from the object side, is a positive lens having the face of large curvature convex on the object side, the 2nd lens is a positive meniscus lens convex on the object side, the 3rd lens is a negative lens having the face of large curvature concave on the image side and the 4th lens is a positive lens disposed apart at a large spacing from the 3rd lens. |
