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).
Diaphragm valve Diaphragm valve Diaphragm valves (or membrane valves) consists of a valve body with two or more ports, a diaphragm, and a "weir or saddle" or seat upon which the diaphragm closes the valve. The valve body may be constructed from plastic, metal, wood or other materials depending on the intended use. Originally, the diaphragm valve was developed for use in industrial applications and/or pipe-organs. Later on the design was adapted for use in the bio-pharmaceutical industry by using compliant materials that can withstand sanitizing and sterilizing methods. There are two main categories of diaphragm valves: one type seals over a