Diaphragm (optics) 1889 "Dictionary of Photography" (see figure), but disappeared after Ernst Abbe's theory of stops unified these concepts. According to Rudolf Kingslake, the inventor of the iris diaphragm is unknown. Others credit Joseph Nicéphore Niépce for this device, around 1820. Mr. J. H. Brown, a member of the Royal Microscopical Society, appears to have invented a popular improved iris diaphragm by 1867. Kingslake has more definite histories for some other diaphragm types, such as M. Noton's adjustable "cat eye" diaphragm of two sliding squares in 1856, and the Waterhouse stops of John Waterhouse in 1858. Diaphragm (optics) In optics, a diaphragm
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