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 Devil's Flower The Devil's Flower The Devil's Flower () is a 2010 Russian romantic fantasy film directed by Ekaterina Grokhovskaya. The main heroine of the picture Polina is pursued by strange dreams, in which she is invited to go through a living flower on the doors of an ancient castle. Trying to figure out what that means, Polina turns to her friend, fortune teller Nastya. Having visited together the archive of the local library, they steal an old book there, which contains a description of the story that Polina sees in her dreams. At the same time, some pages of the book