image circle

The image circle refers to the circular area projected by a camera or lens where the image remains clear and in focus. It is determined by the lens design and size, and it ensures that the entire sensor or film captures a sharp, distortion-free image. The size of this circle must be large enough to cover the sensor or film surface for proper image formation. If the image circle is too small, parts of the image may appear blurry or vignetted. Different cameras and lenses are designed with specific image circle sizes to suit various formats and applications.