Classification of film films

Movie films are classified in many ways:

According to film specifications, the commonly used ones are:

65mm film (sometimes also called 70mm film, the cost is very high , mostly seen in early high-cost movies and IMAX movies, the 15-perf IMAX image quality is 18K or above, and the ordinary 65mm film quality is about 12K),

35mm film (135 film, the most common, the image quality is about 6K),

16mm film (commonly used in documentaries, image quality 2-4K),

8mm film (commonly used in early entertainment and home cameras, image quality is very average).

Classification according to color Film can be divided into black and white film and color film.

Black and white film: Silver halide photosensitive agent is coated on a transparent film base. Color films are produced using subtractive color film. The earliest successful subtractive color film was Technicolor, which was launched in 1927. Since the prints were made using dye transfer, it was also called the dye printing method. The inventor was Dr. H.T. Kalmas. According to this method, a relatively complex split-beam camera is used to simultaneously shoot three negatives that experience red, green, and blue light, and then three relief templates are printed from these negatives, which are dyed with cyan, magenta, and red respectively. Yellow and three complementary color dyes are then overprinted on a blank sheet to become a color copy for projection (see dyeing and printing method).

The color film films commonly used in countries around the world in the 1980s were subtractive color multi-layer films. This kind of film has three layers of emulsions that can sense the three primary colors of red, green, and blue, respectively, stacked on the same base. After photographic exposure and development, a color image can be obtained (see the internal coupling method of multi-layer color film). It consists of two main parts: film base and photosensitive emulsion. In addition, there is a protective layer coated on the surface of the emulsion layer to prevent external damage, a bottom layer coated between the emulsion and the film base to promote adhesion between the two, and a back layer coated on the back to prevent halo, anti-static and anti-curling.