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Cellulose acetate is also known as "safety" film and started to replace nitrate film in still photography in the 1920s. [1] There are several types of acetate that were produced after 1925, which include diacetate (c. 1923 – c. 1955), acetate propionate (1927 – c. 1949), acetate butyrate (1936–present), and triacetate (c. 1950 – present). [1]
Nitrocellulose film base manufactured by Kodak can be identified by the presence of the word "nitrate" in dark letters along one edge; the word only in clear letters on a dark background indicates derivation from a nitrate base original negative or projection print, but the film in hand itself may be a later print or copy negative, made on ...
The US Navy has produced an instructional movie about the safe handling and usage of nitrate films which includes footage of a full reel of nitrate film burning under water. The base is so flammable that intentionally igniting the film for test purposes is recommended in quantities no greater than one frame without extensive safety precautions.
Nitrate sheet film was used widely though the 1930s, while nitrate roll film was used through the 1950s. The nitrate base was replaced with cellulose acetate in 1923. By 1937, Cellulose diacetate was used as the base, and beginning in 1947 Cellulose triacetate was used. [6] Polyester film was introduced around 1960. [7] 1935: Color photographs
The great majority of films made in the silent era are now considered to be lost forever. [6] Movies of the first half of the 20th century were filmed on an unstable, highly flammable cellulose nitrate film base, which required careful storage to slow its inevitable process of decomposition over time. [5]
The first step is transforming raw cellulose into nitrocellulose by conducting a nitration reaction. This is achieved by exposing the cellulose fibers to an aqueous solution of nitric acid; the hydroxyl groups (-OH) will then be replaced with nitrate groups (-ONO 2) on the cellulose chain. The reaction can produce mixed products, depending on ...
Photographic emulsion is a light-sensitive colloid used in film-based photography. Most commonly, in silver-gelatin photography, it consists of silver halide crystals dispersed in gelatin. The emulsion is usually coated onto a substrate of glass, films (of cellulose nitrate, cellulose acetate or polyester), paper, or fabric.
With concerns regarding the instability of nitrate film and the inherent dangers of storing it, many safety features were incorporated into the design and construction of Lubinville's one-story "fireproof" vault, which according to news accounts occupied a total area of 2,000 square feet (190 m 2) with perimeter walls of red brick 13 inches (33 ...