Zoom camera having electronic exposure control
AssigneeEastman Kodak Company
InventorStanley W. Stephenson
Life of this patent
Estimating the term…
Abstract
A photographic camera for taking photographs of a scene having a film speed determining system, an electronically controllable picture taking lens that can be positioned to a plurality of lens focal lengths, a lens selection system for operation by the camera user to select one of the lens focal lengths at which the user wants the picture taking lens to be positioned, and a light sensing system that detects the amount of ambient light illuminating the scene, includes a controller responsive to film speed, available ambient light, and light gathering capacity of the picture taking lens at a selected lens focal length, for determining if the photograph will be underexposed at the selected lens focal length and inhibiting the taking for underexposed photographs.
Claims10
A photographic camera comprising a body, means for determining the speed of film loaded into said camera body, a zoom taking lens that can be positioned to a plurality of focal lengths, positioning means for positioning said zoom lens to a selected focal length, and light sensing means for detecting the amount of ambient light available for illuminating the scene, is characterized by:
- a control means responsive to said film speed sensing means, said light sensing means, and said positioning means, for determining if the photograph will be underexposed at a selected lens focal length.
A method of making photographic exposures in a camera comprising a film speed determining system, an electronically controllable picture taking lens that can be positioned to a plurality of lens focal lengths, a lens selection system for operation by the camera user to select one of the lens focal lengths at which the user wants the picture taking lens to be positioned, and a light sensing system that detects the amount of ambient light illuminating the scene, the method characterized by:
- selecting a lens focal length;
- sensing available ambient light and light gathering capacity of the picture taking lens at the selected lens focal length;
- sensing film speed;
- determining the maximum focal length of the picture taking lens based on ambient light value and film speed;
- comparing the maximum focal length with the selected lens focal length;
- and
- determining if the photograph will be underexposed at the selected lens focal length.
Dependencies are inferred from the claim text.