Human eye The upper end of the range is given in terms of normal visual performance as 10 cd/m (100,000,000 or one hundred million candelas per square meter). The eye includes a lens similar to lenses found in optical instruments such as cameras and the same physics principles can be applied. The pupil of the human eye is its aperture; the iris is the diaphragm that serves as the aperture stop. Refraction in the cornea causes the effective aperture (the entrance pupil) to differ slightly from the physical pupil diameter. The entrance pupil is typically about 4 mm in diameter, although it
The Stone Flower (1946 film) The Stone Flower (1946 film) The Stone Flower () is a 1946 Soviet fantasy film directed by Aleksandr Ptushko. It is an adaptation of Pavel Bazhov's story of the same name, in turn based on Ural region Russian folklore. It also incorporates plot elements from the stories "The Mistress of the Copper Mountain" and "The Master Craftsman". "The Stone Flower" was theatrically released by Mosfilm on 28 April 1946. It was the Soviet Union's first color film shot on Agfacolor negative film seized in Germany, and was entered into the 1946 Cannes Film Festival. It was a success at the