Diaphragm (optics) photographic lens is called an iris diaphragm. In the early years of photography, a lens could be fitted with one of a set of interchangeable diaphragms , often as brass strips known as Waterhouse stops or Waterhouse diaphragms. The iris diaphragm in most modern still and video cameras is adjusted by movable blades, simulating the iris of the eye. The diaphragm has two to twenty blades (with most lenses today featuring between five and ten blades), depending on price and quality of the device in which it is used. Straight blades result in polygon shape of the diaphragm opening, while
Sigurd Snake-in-the-Eye Snake-in-the-eye features prominently in History Channel's historical drama television series "Vikings" played by David Lindström. Sigurd Snake-in-the-Eye Sigurd Snake-in-the-eye (Old Norse: Sigurðr ormr í auga) was a Viking warrior in the middle of the 9th Century. He was supposedly one of the sons of the legendary Viking Ragnar Lothbrok. "Snake-in-the-eye" as part of Sigurd's name denoted a physical characteristic. He was born with a mark in his eye, described as the image of the Ouroboros (a snake biting its own tail). The snake mark had been prophesied by his mother Aslaug, the daughter of the Valkyrie Brynhildr. As a boy,