This first basic type of film is usually sensitive to only blue light and is called an orthochromatic film. Photographic paper is orthochromatic which allows us to work in the darkroom with a safelight that puts out any color but blue. From the basic ortho film we add more sensitizing agents and get a panchromatic film. Pan film records an image for ALL colors of the visible light spectrum as well as a little of the ultra violet and infrared outside of the visible light. Finally we get color film by taking three diferent emulsion layers and putting them on one roll of film.
Film comes in rolls, sheets or in bulk .
For out class we will use 35mm film that comes in a length of 24 exposures. The film also comes in 36 exposures to a roll. Film rolls come in other sizes like 120 or 220 which is film more than twice as large as 35mm film. The larger the film the better or bigger enlargements that can be made from it. Film can be purchased in sheets that are 4x5, 8x10 or larger in size for use in studio view cameras.