| 摘要 |
The invention relates to a focusing method for a camera and camera where the lens system (10) is attached in a fixed manner to the body (14) of the camera at a fixed distance from the photosensitive surface (12) of the camera. Rays of light (S) coming from a target to be photographed are focused onto the photosensitive surface by placing between the lens system (10) and photosensitive surface one or more focusing plate(s) (16) made of a material that lets light pass through and the both surfaces of which are flat. The focusing plate is made of a material the index of refraction of which is greater than one, whereby rays of light will be refracted at the surfaces of the plate as they travel through the focusing plate. Refraction of the rays of light changes their course of propagation, which makes it possible to focus the camera to different ranges. The focusing plate is attached to the camera in a movable manner so that it can be moved between the lens and the photosensitive surface whenever required in order to focus the camera accurately. The focusing plates may have the same thickness throughout or they may become thinner towards one end. In an advantageous embodiment of the invention the camera includes an actuator for moving the focusing plates.
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