An image, or image point or region, is '''''in focus''''' if light from object points is converged almost as much as possible in the image, and '''''out of focus''''' if light is not well converged. The border between these is sometimes defined using a circle of confusion criterion. | An image, or image point or region, is '''''in focus''''' if light from object points is converged almost as much as possible in the image, and '''''out of focus''''' if light is not well converged. The border between these is sometimes defined using a circle of confusion criterion. |