C-41 Process - Use With Black-and-white Films

Use With Black-and-white Films

While C-41 is usually considered a color process, Kodak, an American company, manufactures a C-41 black-and-white film called BW400CN. Ilford, a British company, produces a similar film known as XP2 Super. Fuji, a Japanese company, markets a third film called Neopan 400CN, which is also manufactured by Ilford.

These films work like any other C-41 film; development causes dyes to form in the emulsion. Their structure, however, is different. Although they may have multiple layers, all are sensitive to all colors of light, and are designed to produce a black dye. The result is a black-and white image.

The Kodak film has the same orange base as color C-41 films; the base on the Ilford and Fuji films are clear. The orange base on the Kodak film allows them to be printed with correct blacks on standard color printing machines, but this film can be difficult to print on multigrade black-and-white paper, whose contrast is determined by the use of a colored filter during the printing process. Conversely, the clear-based Ilford and Fuji films sometimes results in off-color prints on color paper, but can be optically printed on black-and-white paper, just like any other black-and-white film.

It is often said that prints from these films do not have grain. While they may not appear to have grain, this statement is technically incorrect. On an image from regular black-and-white film, the individual silver particles forming the image are seen as grain. The image on the C-41 films, however, does not contain silver. Instead, C-41 negatives and prints have clouds of dye, causing the resulting image to appear different from that of silver grain.

Some photographers have used C-41 developer to develop high-contrast black-and-white films, such as traffic surveillance film and Kodak's Technical Pan film; this is done in order to lower the contrast. In this application, only a silver image is formed; the bleach step of the C-41 process is not used, as it would destroy the image.