"""Macro"" Photographic lens having long focal length and vibration compensation"

US5825546A · kind A · utility

Assignee

• NIKON CORPORATION · JP

Inventor

• Sei Matsui

Key dates

• Filing date: Jan 9, 1997
• Grant date: Oct 20, 1998
• Expiry date: Jan 9, 2017

Classification

• Technology area (CPC G): Physics
• CPC primary: G02B27/646
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

Macro telephoto lenses are disclosed for photographic use and that have a vibration compensation. The lenses have a relatively long focal length (as telephoto lenses), having a field of view of about 18.degree. or less and an F number of at least 4. Focusing is from infinity to a reproduction ratio of at least 1/2 and preferably 1/1 or more. The vibration compensation feature comprises at least one "antivibration lens element" in a lens group that is stationary in the direction of the optical axis. The antivibration lens element is operable to be transversely moved relative to the optical axis to counteract the effect of vibration and/or lens movement during photography. The lens preferably comprises a first positive lens group, a second positive lens group, a third negative lens group, and a fourth positive lens group. The first and third lens groups are preferably movable on the optical axis during focusing, and the second and fourth lens groups are preferably stationary in the direction of the optical axis during focusing. The lens preferably fulfills several conditional expressions.