Diaphragm (optics) curved blades improve the roundness of the iris opening. In a photograph, the number of blades that the iris diaphragm has can be guessed by counting the number of diffraction spikes converging from a light source or bright reflection. For an odd number of blades, there are twice as many spikes as there are blades. In case of an even number of blades, the two spikes per blade will overlap each other, so the number of spikes visible will be the number of blades in the diaphragm used. This is most apparent in pictures taken in the dark with small
Daisy (given name) Daisy (given name) Daisy is a feminine given name, commonly thought to be derived from the name of the flower. The flower name comes from the Old English word "dægeseage", meaning "day's eye". The name Daisy is therefore ultimately derived from this source. Daisy is also a nickname for Margaret, used because "Marguerite", the French version of that name, is also a French name for the oxeye daisy. It came into popular use in the late Victorian era along with other flower names. Authors Linda Rosenkrantz and Pamela Redmond Satran wrote in their 2007 book "Baby Name Bible" that Daisy