Telephoto lens system

Details Telephoto lens system Telephoto lens system

1989-07-25

1990-10-30

Arnold, Bruce Y.

G02B 1302

Patent

active

049664492

ABSTRACT:
A telephoto lens system utilizing an inner focusing method, for use in a 35-mm single-lens reflex camera, and despite its lightweight, compact size ensures high performance, and which performs focusing by moving only one lens unit. Performance of the telephoto lens system includes: having a telephoto ratio of no more than 0.7, yet compensating for aberrations when focused upon an object at infinity; adopting an inner focusing method, yet being capable of focusing at the closest distance which is no greater than 7 times the focal length for infinity; and performing near focusing without causing great aberrational variations. The telephoto lens system, in order from the object side, includes: a first lens unit having a positive refractive power; a second lens unit having a weak refractive power; and a third lens unit having a negative refractive power, and which performs focusing for an object at a finite distance by movement of the third lens unit.

REFERENCES:
patent: 4812026 (1989-03-01), Iima

Affiliated with

Also associated with

Rating

Telephoto lens system does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Telephoto lens system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Telephoto lens system will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-272305