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
The Torment of a Flower The Torment of a Flower The Torment of a Flower (), also known as Rainy Night Flower, is a Taiwanese Hokkien song composed by Teng Yu-hsien (; 1906 - 1944) and written by Chou Tien-wang (). A Taiwanese writer Liau Han-sin (廖漢臣) wrote the lyrics of a children's song ""Spring"" (春天) and gave it to Teng Yu-hsien to ask him to compose for it, it's the earliest version of "The Torment of a Flower." Although Teng is a Hakkan, he usually composed with Taiwanese Hokkien but not Hakkan. It is worth noting that some scholars have questioned this story about