Photographic developer in the context of Photographic fixer

Photography is the art, application, and practice of creating images by recording light, either electronically by means of an image sensor, or chemically by means of a light-sensitive material such as photographic film. It is employed in many fields of science, manufacturing (e.g., photolithography), and business, as well as its more direct uses for art, film and video production, recreational purposes, hobby, and mass communication. A person who operates a camera to capture or take photographs is called a photographer, while the captured image, also known as a photograph, is the result produced by the camera.

Typically, a lens is used to focus the light reflected or emitted from objects into a real image on the light-sensitive surface inside a camera during a timed exposure. With an electronic image sensor, this produces an electrical charge at each pixel, which is electronically processed and stored in a digital image file for subsequent display or processing. The result with photographic emulsion is an invisible latent image, which is later chemically "developed" into a visible image, either negative or positive, depending on the purpose of the photographic material and the method of processing. A negative image on film is traditionally used to photographically create a positive image on a paper base, known as a print, either by using an enlarger or by contact printing.

A latent image is an invisible image produced by the exposure to light of a photosensitive material such as photographic film. When photographic film is developed, the area that was exposed darkens and forms a visible image. In the early days of photography, the nature of the invisible change in the silver halide crystals of the film's emulsion coating was unknown, so the image was said to be "latent" until the film was treated with photographic developer.

In more physical terms, a latent image is a small cluster of metallic silver atoms formed in or on a silver halide crystal due to reduction of interstitial silver ions by photoelectrons (a photolytic silver cluster). If intense exposure continues, such photolytic silver clusters grow to visible sizes. This is called printing out the image. On the other hand, the formation of a visible image by the action of photographic developer is called developing out the image.

Photographic paper is a paper coated with a light-sensitive chemical, used for making photographic prints. When photographic paper is exposed to light, it captures a latent image that is then developed to form a visible image; with most papers the image density from exposure can be sufficient to not require further development, aside from fixing and clearing, though latent exposure is also usually present. The light-sensitive layer of the paper is called the emulsion, and functions similarly to photographic film. The most common chemistry used is gelatin silver, but other alternatives have also been used.

The print image is traditionally produced by interposing a photographic negative between the light source and the paper, either by direct contact with a large negative (forming a contact print) or by projecting the shadow of the negative onto the paper (producing an enlargement). The initial light exposure is carefully controlled to produce a grayscale image on the paper with appropriate contrast and gradation. Photographic paper may also be exposed to light using digital printers such as the LightJet, with a camera (to produce a photographic negative), by scanning a modulated light source over the paper, or by placing objects upon it (to produce a photogram).

The Kodak verifax is a photo copying approach that uses a wet colloidal diffusion transfer technique patented by Yutzy, H.C. and Yackel, E.C. (1947) The light source is projected to the top crossing the negative being reflected -more or less, according to the color- against the original to be copied exposing the negative. Has a base that contains the recipient with the liquid developer and the exposure timer.

Due to its extreme simplicity, the method was commonplace until the late 1960s, when it was surpassed by the popularity of the xerocopies using plain paper. Copies had some chemical smell and lost contrast over time.

Cinematography (from Ancient Greek κίνημα (kínēma) 'movement' and γράφειν (gráphein) 'to write, draw, paint, etc.') is the art of motion picture (and more recently, electronic video camera) photography.

Cinematographers use a lens to focus reflected light from objects into a real image that is transferred to some image sensor or light-sensitive material inside the movie camera. These exposures are created sequentially and preserved for later processing and viewing as a motion picture. Capturing images with an electronic image sensor produces an electrical charge for each pixel in the image, which is electronically processed and stored in a video file for subsequent processing or display. Images captured with photographic emulsion result in a series of invisible latent images on the film stock, which are chemically "developed" into a visible image. The images on the film stock are projected for viewing in the same motion picture.

Sensitometry is the scientific study of light-sensitive materials, especially photographic film. The study has its origins in the work by Ferdinand Hurter and Vero Charles Driffield (circa 1876) with early black-and-white emulsions. They determined how the density of silver produced varied with the amount of light received, and the method and time of development.