Diaphragm (optics) bright spots, for example night cityscapes. Some cameras, such as the Olympus XA or lenses such as the MC Zenitar-ME1, however, use a two-bladed diaphragm with right-angle blades creating a square aperture. Similarly, out-of-focus points of light (circles of confusion) appear as polygons with the same number of sides as the aperture has blades. If the blurred light is circular, then it can be inferred that the aperture is either round or the image was shot "wide-open" (with the blades recessed into the sides of the lens, allowing the interior edge of the lens barrel to effectively become the iris).
Compound eye brain. This is called the schizochroal compound eye or the neural superposition eye (which, despite its name, is a form of the apposition eye). The second type is named the superposition eye. The superposition eye is divided into three types; the refracting, the reflecting and the parabolic superposition eye. The refracting superposition eye has a gap between the lens and the rhabdom, and no side wall. Each lens takes light at an angle to its axis and reflects it to the same angle on the other side. The result is an image at half the radius of the eye, which