h a small hole to form an image. With a large pinhole, the image spot is large, resulting in a blurry image.With a large pinhole, the image spot is large, resulting in a blurry image. With a small pinhole, light is reduced and diffraction prevents the image spot from getting arbitrarily small.With a small pinhole, light is reduced and diffraction prevents the image spot from getting arbitrarily small. With a simple lens, much more light can be brought into sharp focus.With a simple lens, much more light can be brought into sharp focus. කාච විවරය සහ නාභි දුර[සංස්කරණය]Large (top) and small (bottom) apertures on the same lens.How focal length affects photograph composition: adjusting the camera's distance from the main subject while changing focal length, the main subject can remain the same size, while the other at a different distance changes size.Focal lengths are usually specified in millimetres (mm), but older lenses might be marked in centimetres (cm) or inches. For a given film