Color photography in the context of Color Developing Agent 3

Color (or colour in Commonwealth English) is the visual perception produced by the activation of the different types of cone cells in the eye caused by light. Though color is not an inherent property of matter, color perception is related to an object's light absorption, emission, reflection and transmission. For most humans, visible wavelengths of light are the ones perceived in the visible light spectrum, with three types of cone cells (trichromacy). Other animals may have a different number of cone cell types or have eyes sensitive to different wavelengths, such as bees that can distinguish ultraviolet, and thus have a different color sensitivity range. Animal perception of color originates from different light wavelength or spectral sensitivity in cone cell types, which is then processed by the brain.

Colors have perceived properties such as hue, colorfulness, and lightness. Colors can also be additively mixed (mixing light) or subtractively mixed (mixing pigments). If one color is mixed in the right proportions, because of metamerism, they may look the same as another stimulus with a different reflection or emission spectrum. For convenience, colors can be organized in a color space, which when being abstracted as a mathematical color model can assign each region of color with a corresponding set of numbers. As such, color spaces are an essential tool for color reproduction in print, photography, computer monitors, and television. Some of the most well-known color models and color spaces are RGB, CMYK, HSL/HSV, CIE Lab, and YCbCr/YUV.

Hand-colouring (or hand-coloring) refers to any method of manually adding colour to a monochrome photograph, generally either to heighten the realism of the image or for artistic purposes. Hand-colouring is also known as hand painting or overpainting.

Typically, watercolours, oils, crayons or pastels, and other paints or dyes are applied to the image surface using brushes, fingers, cotton swabs or airbrushes. Hand-coloured photographs were most popular in the mid- to late-19th century before the invention of colour photography, and some firms specialized in producing hand-coloured photographs.

Subtractive color or subtractive color mixing predicts the spectral power distribution of light after it passes through successive layers of partially absorbing media. This idealized model is the essential principle of how dyes and pigments are used in color printing and photography, where the perception of color is elicited after white light passes through microscopic "stacks" of partially absorbing media, allowing some wavelengths of light to reach the eye and not others. It is also a concept seen in painting, wherein the colors are mixed or applied in successive layers, though predicting realistic results (such as blue and yellow mixing to produce green instead of gray) requires more complex models such as Kubelka–Munk theory.

Monochrome photography is photography where each position on an image can record and show a different amount of light (value), but not a different color (hue). The majority of monochrome photographs produced today are black-and-white, either from a gelatin silver process, or as digital photography. Other hues besides grey can be used to create monochrome photography, but brown and sepia tones are the result of older processes like the albumen print, and cyan tones are the product of cyanotype prints.

As monochrome photography provides an inherently less complete reproduction than color photography, it is mostly used for artistic purposes and certain technical imaging applications.

Louis Arthur Ducos du Hauron (8 December 1837 – 31 August 1920) was a French pioneer of color photography.

Dye coupler is present in chromogenic film and paper used in photography, primarily color photography. When a color developer reduces ionized (exposed) silver halide crystals, the developer is oxidized, and the oxidized molecules react with dye coupler molecules to form a dye in situ. The silver image is removed by subsequent bleach and fix processes, so the final image will consist of the dye image.

Dye coupler technology has seen considerable advancement since the beginning of modern color photography. Major film and paper manufacturers have continually improved the stability of the image dye by improving couplers, particularly since the 1980s, so that archival properties of images are enhanced in newer color papers and films. Generally speaking, dye couplers for paper use are given more emphasis on the image permanence than those for film use, but some modern films (such as Fujichrome Provia films) use variants of couplers that were originally designed for paper use to further improve the image permanence.

Color motion picture film refers both to unexposed color photographic film in a format suitable for use in a motion picture camera, and to finished motion picture film, ready for use in a projector, which bears images in color.

The first color cinematography was by additive color systems such as the one patented by Edward Raymond Turner in 1899 and tested in 1902. A simplified additive system was successfully commercialized in 1909 as Kinemacolor. These early systems used black-and-white film to photograph and project two or more component images through different color filters.

Fujifilm Holdings Corporation (富士フイルムホールディングス株式会社, Fuji-fuirumu Hōrudingusu kabushiki gaisha), trading as Fujifilm (富士フイルム, Fuji-fuirumu), or simply Fuji, is a Japanese multinational conglomerate headquartered in Tokyo, Japan, operating in the areas of photography, optics, office and medical electronics, biotechnology, and chemicals.

The company started as a manufacturer of photographic films, which it still produces. Fujifilm products include document solutions, medical imaging and diagnostics equipment, cosmetics, pharmaceutical drugs, regenerative medicine, stem cells, biologics manufacturing, magnetic tape data storage, optical films for flat-panel displays, optical devices, photocopiers, printers, digital cameras, color films, color paper, photofinishing and graphic arts equipment and materials.

The fourth in the series of color developing agents used in developing color films, commonly known as CD-4, is chemically known as 4-(N-Ethyl-N-2-hydroxyethyl)-2-methylphenylenediamine sulfate. In color development, after reducing a silver atom in a silver halide crystal, the oxidized developing agent combines with a color coupler to form a color dye molecule.

Jacques-Yves Cousteau, AC (/kuːˈstoʊ/, also UK: /ˈkuːstoʊ/; French: [ʒak iv kusto]; 11 June 1910 – 25 June 1997) was a French naval officer, oceanographer, filmmaker and author. He co-invented the first successful open-circuit self-contained underwater breathing apparatus (SCUBA), called the Aqua-Lung, which assisted him in producing some of the first underwater documentaries.

Cousteau wrote many books describing his undersea explorations. In his first book, The Silent World: A Story of Undersea Discovery and Adventure, Cousteau surmised the existence of the echolocation abilities of porpoises. The book was adapted into an underwater documentary called The Silent World. Co-directed by Cousteau and Louis Malle, it was one of the first films to use underwater cinematography to document the ocean depths in color. The film won the 1956 Palme d'Or at the Cannes Film Festival and remained the only documentary to do so until 2004 (when Fahrenheit 9/11 received the award). It was also awarded the Academy Award for Best Documentary in 1957.

Color (or colour in Commonwealth English; see spelling differences) is the visual perception based on the electromagnetic spectrum. Though color is not an inherent property of matter, color perception is related to an object's light absorption, emission, reflection and transmission. For most humans, visible wavelengths of light are the ones perceived in the visible light spectrum, with three types of cone cells (trichromacy). Other animals may have a different number of cone cell types or have eyes sensitive to different wavelengths, such as bees that can distinguish ultraviolet, and thus have a different color sensitivity range. Animal perception of color originates from different light wavelength or spectral sensitivity in cone cell types, which is then processed by the brain.

Colors have perceived properties such as hue, colorfulness, and lightness. Colors can also be additively mixed (mixing light) or subtractively mixed (mixing pigments). If one color is mixed in the right proportions, because of metamerism, they may look the same as another stimulus with a different reflection or emission spectrum. For convenience, colors can be organized in a color space, which when being abstracted as a mathematical color model can assign each region of color with a corresponding set of numbers. As such, color spaces are an essential tool for color reproduction in print, photography, computer monitors, and television. Some of the most well-known color models and color spaces are RGB, CMYK, HSL/HSV, CIE Lab, and YCbCr/YUV.