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).
Thoracic diaphragm more consistently lower position of the diaphragm increases intra-abdominal pressure which strengthens the lumbar spine. The key to real core stabilization is to maintain the increased IAP while going through normal breathing cycles. […] The diaphragm then performs its breathing function at a lower position to facilitate a higher IAP. Therefore, if a person more consistently lowers their diaphragm, through deep breathing, this can assist strengthening of the core during that period. This can be an aid in strength training and other forms of athletic endeavour. For this reason, taking a deep breath, or adopting a deeper breathing pattern, is