Film photography is a form of photography in which a light sensitive photographic film is exposed to an optical image and subsequently chemically processed to produce a negative or positive photographic record. Photographic film normally consists of a flexible base coated with one or more layers of light sensitive emulsion containing silver halide crystals. When light reaches the emulsion, it produces a latent image that is not immediately visible.
Chemical development converts the latent information into a visible image, while fixing removes remaining light sensitive silver compounds so that the film can be viewed in ordinary light. Film photography is a specific and important category within analogue photography, although analogue photography historically includes processes that do not use flexible film. The term film photography therefore identifies the recording material as well as the broader photographic workflow associated with film cameras, chemical processing, negatives, transparencies, and photographic printing.
Photographic film is manufactured in several forms and sizes. Roll film is wound onto a spool and is commonly associated with medium format cameras, while 35 millimetre film is supplied in cartridges or cassettes and is widely associated with compact and professional cameras. Sheet film consists of individual pieces used in large format cameras and permits extensive control over composition, perspective, focus, and depth of field. Film is also available in different emulsions designed for different purposes.
Black and white negative film records tonal information through varying densities of metallic silver. Colour negative film uses several colour sensitive layers and produces complementary colour information that can be converted into a positive print. Colour reversal film produces a positive transparency that can be viewed directly or projected. Each material has different processing requirements and visual characteristics.
The exposure process in film photography is controlled by the same basic optical variables found in other camera systems. Aperture determines the diameter of the lens opening and affects both exposure and depth of field. Shutter speed determines how long light reaches the film and influences motion rendering. Film sensitivity is expressed using standards such as ISO, with more sensitive films requiring less light but generally showing greater grain or other changes in image characteristics.
Film has an exposure response that differs from digital sensors, and different emulsions can have different latitude, contrast, colour response, reciprocity behaviour, and spectral sensitivity. Reciprocity failure can occur during very long exposures when the relationship between exposure time and required light is no longer linear. Photographers therefore need to understand both the camera and the particular film stock being used rather than assuming that all film behaves identically.
A distinctive feature of film photography is the separation between exposure and image evaluation. After the shutter is released, the photographer normally cannot see the final negative or transparency until the film has been processed. This creates a delayed workflow in which exposure decisions must be based on experience, metering, visual judgement, and sometimes bracketing. Once a roll is completed, it must be rewound or removed and processed.
Processing can be performed in a professional laboratory or personally using appropriate chemistry and equipment. Black and white film is comparatively accessible for home processing because development chemistry and temperature control can be managed on a small scale, while colour processes generally require more precise chemical and temperature control. The delay and physical dependency can influence photographic practice by encouraging deliberate capture and careful management of exposures.
Film photography has a major relationship with photographic negatives and printing. A negative reverses the brightness relationships of the original scene, so bright areas of the subject appear relatively dense and dark on a conventional negative, while dark areas appear relatively transparent. A photographic enlarger can project light through the negative onto photosensitive paper, reversing the tonal relationships again and creating a positive print.
Colour negative printing similarly uses the negative to control the formation of complementary colour dyes in photographic paper. Alternatively, film can be scanned and converted into digital files. A processed film negative is therefore not necessarily the final photograph. It is often an intermediate original from which many different positive representations can be created. This distinction is particularly important in archival collections because the negative may contain information that is not fully represented in an individual historical print.
Film characteristics are partly responsible for the visual qualities associated with film photography. Grain results from the physical structure of the photographic emulsion and can become more prominent with faster films, enlargement, or particular development methods. Tonal response in black and white film can be modified through choice of developer, dilution, agitation, temperature, and development time. Colour film has characteristic responses to different wavelengths of light and can produce distinctive colour rendition depending on the emulsion and processing.
Different films may vary in contrast, saturation, sharpness, grain, exposure latitude, and response to underexposure or overexposure. These properties are sometimes described as the look of a film stock. However, many visual characteristics can also be influenced by lenses, filters, exposure, scanning, printing, lighting, and subsequent editing, so the appearance of a photograph cannot reliably be attributed to film alone.
Film photography has been used extensively in journalism, portraiture, landscape photography, advertising, scientific documentation, cinema related still photography, family photography, identification, surveillance, and fine art. Different formats became associated with different practical requirements. Small format 35 millimetre film offered portability and large numbers of exposures, medium format provided larger negatives or transparencies, and large format offered exceptional control and image detail. Professional photographers historically selected film according to subject, lighting, required enlargement, colour requirements, and processing facilities.
The development of highly sensitive films, improved emulsions, motorised cameras, and sophisticated exposure meters made film practical across a wide range of conditions. Although digital cameras replaced film for most everyday and commercial capture, film continues to be manufactured and used by photographers who value its physical workflow, specific material characteristics, historical continuity, or compatibility with traditional darkroom practice.
Preserving film photographs requires attention to both the film material and any associated photographic prints or digital scans. Black and white negatives can be relatively stable when properly processed and stored, but deterioration can still result from heat, humidity, pollutants, physical handling, light exposure, fungal growth, and residual processing chemicals. Some acetate film bases can suffer from vinegar syndrome, a chemical deterioration associated with acetic acid release that causes characteristic odour, shrinkage, embrittlement, and dimensional changes.
Nitrate film presents additional historical preservation concerns because nitrate cellulose is chemically unstable and can become a serious fire hazard as it deteriorates. Polyester based films are generally more dimensionally stable. Archival storage therefore involves controlled temperature and relative humidity, suitable enclosures, clean handling, proper identification, and appropriate duplication or digitisation. Film photography is consequently both a photographic technology and a material record that requires specialised preservation knowledge.
