Kuvaalue

Kuvaalue, or image area, is the rectangular portion of a scene that a camera, microscope, or other imaging device records on its sensor or image plane. It describes both what is captured and the area of the resulting image, and it is determined by the combination of the lens or objective and the recording medium (sensor or film). In practice, a larger image area means more of the scene is included in the frame, while a smaller area corresponds to tighter framing or cropping.

In photography and videography, the image area is closely tied to sensor size and focal length. The field of view describes how much of the scene appears in the image and is influenced by these factors. For a rectangular sensor, the horizontal and vertical fields of view can be expressed approximately as 2 arctan(W/(2f)) and 2 arctan(H/(2f)), where W and H are the sensor width and height and f is the focal length. Cropping or using a smaller portion of the sensor reduces the image area and can decrease the effective resolution. The aspect ratio of the sensor also constrains the shape of the image area.

In optical disciplines such as microscopy and astronomy, the term is often used to refer to the field of view on the specimen or sky, typically measured in millimeters or degrees. The visible area depends on the objective or instrument configuration and can vary with magnification and eyepiece choices. Understanding the image area is essential for planning framing, resolution requirements, and subsequent processing or printing of images.