Angular aperture

About: Angular aperture is a research topic. Over the lifetime, 1771 publications have been published within this topic receiving 27257 citations.

Vis-infrared correctiv fisheye lens system for extreme temperatures

Abstract: An vis-infrared corrective fisheye lens system is provided with, from upstream to downstream, a first lens of negative meniscus, a second lens of biconcave, a third lens of biconvex, an aperture, a fourth lens of biconvex, a fifth lens of negative meniscus, a sixth lens of biconvex, an exchangeable optical filter, and an imaging plane. The lens system has an ultra wide angle of about 210-degree and is capable of operating in a temperature range of −15° C.-80° C. so that the lens system can be mounted in a surveillance system in a vehicle or an outdoor place.

Zoom lens and image pickup apparatus equipped with same

Abstract: A zoom lens has a negative object side lens unit (or first lens unit G 1 ), a positive image side lens unit (or third lens unit G 3 ), a positive intermediate lens unit (or second lens unit G 2 ), and an aperture stop. The distance between the object side lens unit and the intermediate lens unit is smaller at the telephoto end than at the wide angle end, the distance between the intermediate lens unit and the image side lens unit is larger at the telephoto end than at the wide angle end, the intermediate lens unit moves in such a way that it is located closer to the object side at the telephoto end than at the wide angle end, the image side lens unit moves in such a way that it is located closer to the image side at the telephoto end than at the wide angle end, the aperture stop moves integrally with the intermediate lens unit. The image side lens unit is composed of two lens component including a front lens component and a positive rear lens component arranged in the mentioned order from the object side. The absolute value of the paraxial radius of curvature of the image side lens surface of the front lens component is smaller than the absolute value of the paraxial radius of curvature of the object side surface of the rear lens component.

Short focal length imaging device

Abstract: An imaging device is disclosed which comprises a noble metal photosensitive glass having formed on the surfaces a plurality of raised spherical surfaces which form an array of thick lenses. The array can be positioned between an object and image plane to project images from the object plane onto the image plane. Lens spherical aberrations are reduced and lens array imaging performance is optimized by an optimum lens aperture radius or an optimum lens numerical aperture.

High aperture objective

Abstract: This invention relates to lenses and particularly to high aperture photographic objectives. It is an object of the invention to provide a high aperture lens with high covering power and good correction for the various aberrations including spherical aberration, chromatic aberration, lateral...

Photographic lens system having an auxiliary lens

Abstract: Disclosed is a lens system having a principal lens, a photographic film and an auxiliary lens which can be mounted between the principal lens and the photographic lens and has a negative refractive power. The auxiliary lens consisting of a first positive lens having a front surface with large radius and a convex rear surface at the image side, a second bi-concave lens and a third positive lens having a convex front surface at the object side and a rear surface with large radius in sequence from the object side, while the axial distance between the first positive lens and the second bi-concave lens is larger than that between the second bi-concave lens and the third positive lens and the second bi-concave lens and the third positive lens have a negative composed refraction power.