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 seal of this use are: Diaphragm seals are susceptible to failure via several mechanisms, including cracking. Ozone cracking can occur in many elastomers for example used in pneumatic systems. If the gas contaminates the air supply, then many rubber diaphragms are at risk from the problem. Diaphragm seal A diaphragm seal is a flexible membrane that seals and isolates an enclosure. The flexible nature of this seal allows pressure effects to cross the barrier but not the material being contained. Common uses for diaphragm seals are to protect pressure sensors from the fluid whose pressure is being measured. Since diaphragm seals