Photographic film

Photographic film is a strip or sheet of transparent film base with a special layer called gelatin emulsion. This layer has tiny crystals called silver halide that react to light, letting us take photographs. When light passes through a camera lens, it makes an invisible image called a latent image. This image can be made visible through a chemical process called developed.

Film is cut into frames, each holding one picture. Some films can sense special kinds of light, such as ultraviolet light, X-rays, and gamma rays. Early films only saw blue light, but scientists found that special dyes could help films see other colors. This made panchromatic film, which can show all colors in shades of gray.

In black-and-white photographic film, silver halide crystals turn into metallic silver when light hits them, making the dark parts of a picture. Color film uses many layers, each seeing a different color, and special chemicals called color couplers to show all colors. Before digital photography became popular, people had to develop film in a lab or at home to see their pictures.

Characteristics of film

Photographic film is a strip or sheet with a special coating that can capture light to make pictures. The coating has tiny crystals that react to light, deciding how clear and detailed the film looks. Films are divided into separate parts called frames, each holding one picture.

There are different kinds of film. Print film creates negatives, which are then used to make positive prints on paper. Color reversal film makes transparent pictures called slides that can be viewed directly. Black-and-white films also exist but are less common.

Film needs the right amount of light to create a good picture. How much light it needs is called its film speed, measured by ISO. Slower films need more light and give finer details, while faster films work better in dim light or for quick actions. Special films can even capture ultraviolet or infrared light, though they need extra equipment.

History

See also: History of photography

The earliest way to take pictures was the daguerreotype, introduced in 1839. It used chemicals on a silver-plated copper sheet, not film. The calotype process made paper negatives. By the 1850s, thin glass plates coated with photographic emulsion became the standard for cameras. Though fragile and heavy, glass was better than early plastics and cheaper at first. Glass plates were used until the early 2000s for astrophotography and electron micrography, when digital methods took over. Ilford still makes glass plates for special scientific uses.

The first flexible roll film was sold by George Eastman in 1885, but it was coated on paper. The image layer was later moved to a sheet of hardened gelatin. Transparent plastic roll film came in 1889, made from flammable cellulose nitrate film.

Cellulose acetate, or "safety film," was introduced in 1908 but was used only for special purposes. Nitrate film was tougher, clearer, and cheaper, so it stayed standard for theatrical films until 1951.

Hurter and Driffield started studying the light sensitivity of photographic emulsions in 1876. Their work led to the first way to measure film speed. They created H&D curves, which show how each film reacts to light.

Early films worked only with blue, violet, and ultraviolet light. This made skies look white and foliage dark. Photographers sometimes added skies from other photos or adjusted their pictures by hand.

In 1873, Hermann Wilhelm Vogel found that adding dyes could make films sensitive to green and yellow light. These early dyes were unstable and caused fogging, so they were used only in labs at first. By 1883, commercially dye-sensitized plates were sold. They were called isochromatic or orthochromatic.

In 1894, the Lumière Brothers made a plate sensitive to all colors, including red. Better dyes were developed, and in 1902, a more evenly color-sensitive plate was sold by Perutz. Panchromatic emulsions on film became available in the 1910s but were not common until later. Some photographers preferred not to use sensitivity to red, as it was rare in nature, and it required giving up the traditional red darkroom safelight.

Experiments with color photography began early, but the three-color method was not fully accepted until the early 1900s. Good-quality color photos were rare until then.

The first practical color "film" was the Lumière Autochrome, a glass plate product from 1907. It was expensive and not good for quick photos. Film versions came in the early 1930s with better sensitivity. These used a layer of black-and-white emulsion with tiny color filter elements. The slides were very dark because the color filter layer absorbed much light. The last films of this type ended in the 1950s, but Polachrome "instant" slide film revived the technology in 1983.

"Color film" as we know it today began with Kodachrome in 1935 for home movies and 1936 for still cameras. It needed complex processing. In 1936, Agfa Color Neu was the first subtractive three-color reversal film for movies and still cameras. It used dye-forming chemicals and could be processed with a single color developer. This process became the basis for later color films.

Even after World War II, color film was more expensive than black-and-white, needed more light, and cost more to process. These issues slowed its use. But as costs fell, sensitivity improved, and processing became standardized, color film became more common. By the 1970s, it was the main type used by consumers, while black-and-white was mostly used for photojournalism and fine art photography.

Photographic lenses and equipment were designed for the film being used. Early materials were only sensitive to blue-violet light, but lenses were made to focus yellow and violet rays correctly. Orthochromatic emulsions needed all colors from yellow to blue to be in focus. Most plates and films were not sensitive to red, so red lighting could be used in darkrooms without affecting the film. With panchromatic film, the whole spectrum needed sharp focus. Using color film meant lenses had to be even better.

Film was the main way to take pictures until the early 2000s, when digital photography became popular. The first consumer digital camera, the Sony Mavica, came out in 1981. The first digital camera, the Fuji DS-X, was released in 1989. Software like Adobe Photoshop, better printers, and more computers in homes helped digital photography grow.

At first, digital cameras were expensive and had lower resolution than film, but they became popular for point-and-shoot cameras and professional sports photography because they could quickly provide results. Early digital cameras became obsolete fast, forcing people to replace them often. Photographers who needed high quality, like for weddings or fashion, were the last to switch to digital once sensors became better.

Film camera sales peaked in 1998 and dropped sharply after 2000, almost disappearing by 2005 as people moved to digital cameras. Film sales also fell, from about 200 million rolls in 1999 to only 5 million by 2009. This hurt many film companies. Agfa-Gevaert sold its consumer part in 2004. Other companies like Ilford Imaging UK, Agfaphoto, Forte, Foton, Polaroid, Ferrania, and Eastman Kodak faced bankruptcy. Konica-Minolta left the film market in 2006, and Fujifilm moved into other products.

Even though digital photography is now more common, some people still prefer film for its special look.

Despite the popularity of digital cameras, sales of photographic film have been increasing. Kodak and other companies have noticed this trend. Research shows that 60% of current film users started in the past five years, and 30% are under 35 years old. Annual film sales, which dropped to 5 million rolls in 2009, have doubled to about 10 million rolls in 2019. One challenge is that production depends on old facilities, and some steps have been scaled down, causing bottlenecks.

In 2013, Ferrania, an Italian film maker that stopped making films between 2009 and 2010, was bought by a new company. They used old research facilities and re-hired some workers. In November 2013, they started a crowdfunding campaign to buy old tools and machines, which succeeded. In February 2017, they introduced the "P30" 80 ASA, a panchromatic black and white film in 35mm format.

In January 2017, Kodak announced that Ektachrome, a well-known film that stopped being made between 2012 and 2013, would be made again in 35mm still and Super 8 movie formats. Later, Kodak also released it in 120 and 4x5 formats.

Fujifilm’s instant film "Instax" cameras and paper have been very successful and have replaced traditional films as Fujifilm’s main products, while they still offer traditional films in different formats.

In 2023, a Finnish chemist named Sami Vuori invented a reusable film using synthetic hackmanite (Na₈Al₆Si₆O₂₄(Cl,S)₂) as the light-sensitive material. The film turns purple when exposed to ultraviolet light, and visible light turns it back to white, creating a positive image. It can be scanned and colored again with UV light. One advantage is that it doesn’t need gelatin, making it vegan. However, it needs long exposure times, so it’s only good for very long exposures, like fading movement in a city scene.

Image gallery

Photographic film comes in many different sizes and types. Some common types include 9.5mm film, Mycro 17.5mm film, Kodak Agfa 16 mm film, 120 film, and 35mm film.

You can see a range of 35mm film and Soviet Svema film. There is also a guide on a roll of 120 film that shows how many pictures it can take with different frame sizes.