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
Eye of the Tiger Eye of the Tiger "Eye of the Tiger" is a song composed by American rock band Survivor. It was released as a single from their third album of the same name "Eye of the Tiger" and was also the theme song for the film "Rocky III", which was released a day before the single. The song was written by Survivor guitarist Frankie Sullivan and keyboardist Jim Peterik, and was recorded at the request of "Rocky III" star, writer, and director Sylvester Stallone, after Queen denied him permission to use "Another One Bites the Dust", the song Stallone intended as the