Russian-born Alexander Alexeieff and the American Claire Parker are known best for their invention of a new technique in animation: the Pinscreen (called the pinboard until the mid-sixties). The pinscreen itself contains a large number of pins which can be pushed in or out to create variations from black to white, through various grays. The end result is very much like a mezzotint. While they have made pinscreens with as many as a million pins, Alexeieff and Parker did not labour over the position of each pin: instead, they would draw on the field with instruments to bring out the shading. It was very important to them to do animated films as a fine art, rather than as slapstick comedy, and they felt the beauty of the pinscreen images allowed them to explore the artistic possibilities of animation. Their first film, Night on Bald Mountain, was enthusiastically received by the critics of the time. They also made commercial films, and animated books using the pinscreen. For information on a computer simulation of the pinscreen technique, see Pedro Faria Lopes' article, The Pinscreen in the Era of the Digital Image. They did experiments with another animation technique, Totalization of Illusory Solids, which involves shooting footage of a moving object, normally a pendulum, throughout its entire path, creating the appearance of a solid object. The pendulum can then be moved, and re-shot, and the resulting film will show an illusory solid moving through space. Their partnership lasted over 50 years; Parker died in 1981, Alexeieff in 1982. Some of their Films: Night on Bald Mountain, 1933, pinscreen, based on the music of Moussorgsky. En Passant, pinscreen, based on the Canadian folk song, done at the National Film Board of Canada, opened the international festival of Cannes in 1946. The Nose, also on pinscreen, based on Gogol's short story. Pictures at an Exhibition, based on the music of Moussorgsky, this film used two pinscreens, a small revolving one in front of a large stationery one, allowing them more three-dimensionality than stationery pinscreens. Three Moods, another film made using Moussorgsky's music, was made when Claire Parker was 73, and Alexander Alexeieff was 78.