from the market by DVPO theatrical (who marketed these system on behalf of Panavision) citing "challenging global economic and 3D market conditions". Decline In the transition period centered around 2010–2015, the rapid conversion of the cinema exhibition industry to digital projection has seen 35 mm film projectors removed from most of the projection rooms as they were replaced by digital projectors. By the mid-2010s, most of the theaters across the world have been converted to digital projection, while others are still running 35 mm projectors. In spite of the uptake in digital projectors installed in global cinemas, 35 mm film remains in a niche market of enthusiasts and format lovers. Attributes Color Originally, film was a strip of cellulose nitrate coated with black-and-white photographic emulsion. Early film pioneers, like D. W. Griffith, color tinted or toned portions of their movies for dramatic impact, and by 1920, 80 to 90 percent of all films were tinted. The first successful natural color process was Britain's Kinemacolor (1908–1914), a two-color additive process that used a rotating disk with red and green filters in front of the camera lens and the projector lens. But any process that photographed and projected the colors sequentially was subject to color "fringing" around moving objects, and a general color flickering. In 1916, William Van Doren Kelley began developing Prizma, the first commercially viable American color process using 35 mm film. Initially, like Kinemacolor, it photographed the color elements one after the other and projected the results by additive synthesis. Ultimately, Prizma was refined to bipack photography, with two strips of film, one treated to be sensitive to red and the other not, running through the camera face to face. Each negative was printed on one surface of the same duplitized print stock and each resulting series of black-and-white images was chemically toned to transform the silver into a monochrome color, either orange-red or blue-green, resulting in a two-sided, two-colored print that could be shown with any ordinary projector. This system of two-color bipack photography and two-sided prints was the basis for many later color processes, such as Multicolor, Brewster Color and Cinecolor. Although it had been available previously, color in Hollywood feature films first became truly practical from the studios' commercial perspective with the advent of Technicolor, whose main advantage was quality prints in less time than its competitors. In its earliest incarnations, Technicolor was another two-color system