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
As Far as the Eye Can See As Far as the Eye Can See As Far as the Eye Can See is the debut album of Welsh alternative rock band People in Planes (or second album overall, as 2002's "Splendid Animation" was released under the previous band name of Tetra Splendour), released on 28 March 2006. After being dropped by EMI, the band recorded a new album at Wales' Monnow Valley Studio, containing new songs (with newly hired keyboard player Ian Russell) and unreleased Tetra Splendour material. The music video for the album's first single, "If You Talk Too Much (My Head Will Explode)", was directed by