In photography, a dark slide is a wooden or metal plate that covers the sensitized emulsion side of a photographic plate. In use, a pair of plates joined back to back were used with both plates covered with a dark slide. When used, the dark slide is removed for the period of the exposure and then replaced. Modern dark slides are used in conjunction with a film holder, that either holds in place pieces of cut sheet film or, if modified, some piece of light sensitive material such as glass.
Photography is the art, application and practice of creating durable images by recording light or other electromagnetic radiation, 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, and business, as well as its more direct uses for art, film and video production, recreational purposes, hobby, and mass communication.
An emulsion is a mixture of two or more liquids that are normally immiscible. Emulsions are part of a more general class of two-phase systems of matter called colloids. Although the terms colloid and emulsion are sometimes used interchangeably, emulsion should be used when both phases, dispersed and continuous, are liquids. In an emulsion, one liquid is dispersed in the other. Examples of emulsions include vinaigrettes, homogenized milk, and some cutting fluids for metal working.
Mahogany double dark slides
In place, the dark slide is in a film holder or magazine. Film holders usually refer to cut sheet film and magazines refer to roll film. Vintage film holders were made of wood and held in place either photo-sensitized plates or photo sensitive film. In either case, the construction must be such to reduce light leaks, or any unwanted light from striking the film until the holder is held in place by a camera and considered "light tight". Some holders held only one piece of light sensitive material, some are double sided and hold two pieces of film.
Once in the camera with a light tight back and light tight bellows, the dark slide may be pulled out for the exposure to be made from a lens. After the exposure, the dark slide is put back in place and the array is put away, usually in a light tight cloth bag or box until it can be taken into a darkroom for development. The term "dark slide" refers to the fact the slide is pulled or slid out of the frame either plastic or wooden. On sliding it back in, the same channels for holding the dark slide are used to cover the film. Ordinarily, in modern film holders, the opening to permit the dark slide to be removed is protected by a strip of black velour or other black baffling that permits the dark slide to move in and out of the holder while restraining the amount of light used by the dark slide while either in place or removed.
Victor Hasselblad AB is a Swedish manufacturer of medium-format cameras, photographic equipment and image scanners based in Gothenburg, Sweden. The company is best known for the classic medium-format cameras it has produced since World War II.
Mamiya Digital Imaging Co., Ltd. is a Japanese company that manufactures high-end cameras and other related photographic and optical equipment. With headquarters in Tokyo, it has two manufacturing plants and a workforce of over 200 people. The company was founded in May 1940 by camera designer Seiichi Mamiya and financial backer Tsunejiro Sugawara.
A view camera is a large format camera in which the lens forms an inverted image on a ground glass screen directly at the plane of the film. The image viewed is exactly the same as the image on the film, which replaces the viewing screen during exposure.
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A camera is an optical instrument to capture still images or to record moving images, which are stored in a physical medium such as in a digital system or on photographic film. A camera consists of a lens which focuses light from the scene, and a camera body which holds the image capture mechanism.
A pinhole camera is a simple camera without a lens but with a tiny aperture, a pinhole – effectively a light-proof box with a small hole in one side. Light from a scene passes through the aperture and projects an inverted image on the opposite side of the box, which is known as the camera obscura effect.
The daguerreotype process, or daguerreotypy, was the first publicly available photographic process, and for nearly twenty years it was the one most commonly used.
The Speed Graphic is a press camera produced by Graflex in Rochester, New York. Although the first Speed Graphic cameras were produced in 1912, production of later versions continued until 1973; with the most significant improvements occurring in 1947 with the introduction of the Pacemaker Speed Graphic. It was standard equipment for many American press photographers until the mid-1960s.
A box camera is a simple type of camera, the most common form being a cardboard or plastic box with a lens in one end and film at the other. They were very popular in the late 19th and early 20th centuries. The lenses are often single element designs meniscus fixed focus lens, or in better quality box cameras a doublet lens with minimal possible adjustments to the aperture or shutter speeds. Because of the inability to adjust focus, the small lens aperture and the low sensitivity of the sensitive materials available, these cameras work best in brightly lit day-lit scenes when the subject is within the hyperfocal distance for the lens and of subjects that move little during the exposure. Eventually, box cameras with photographic flash, shutter and aperture adjustment were introduced, allowing indoor photos.
Sheet film is large format and medium format photographic film supplied on individual sheets of acetate or polyester film base rather than rolls. Sheet film was initially supplied as an alternative to glass plates. The most popular size measures 4×5 inches; smaller and larger sizes including the gigantic 20×24 inches have been made and many are still available today.
In photography, a negative is an image, usually on a strip or sheet of transparent plastic film, in which the lightest areas of the photographed subject appear darkest and the darkest areas appear lightest. This reversed order occurs because the extremely light-sensitive chemicals a camera film must use to capture an image quickly enough for ordinary picture-taking are darkened, rather than bleached, by exposure to light and subsequent photographic processing.
A darkroom is a workshop used by photographers working with photographic film to make prints and carry out other associated tasks. It is a room that can be made completely dark to allow the processing of the light-sensitive photographic materials, including film and photographic paper. Various equipment is used in the darkroom, including an enlarger, baths containing chemicals, and running water.
Color photography is photography that uses media capable of reproducing colors. By contrast, black-and-white (monochrome) photography records only a single channel of luminance (brightness) and uses media capable only of showing shades of gray.
A contact print is a photographic image produced from film; sometimes from a film negative, and sometimes from a film positive or paper negative. In a darkroom an exposed and developed piece of photographic film or paper is placed emulsion side down, in contact with a piece of photographic paper, light is briefly shone through the negative or paper and then the paper is developed to reveal the final print.
Photogravure is an intaglio printmaking or photo-mechanical process whereby a copper plate is grained and then coated with a light-sensitive gelatin tissue which had been exposed to a film positive, and then etched, resulting in a high quality intaglio plate that can reproduce detailed continuous tones of a photograph.
Sun printing may refer to various printing techniques which use sunlight as a developing or fixative agent.
Gum bichromate is a 19th-century photographic printing process based on the light sensitivity of dichromates. It is capable of rendering painterly images from photographic negatives. Gum printing is traditionally a multi-layered printing process, but satisfactory results may be obtained from a single pass. Any color can be used for gum printing, so natural-color photographs are also possible by using this technique in layers.
A camera magazine is a light-tight chamber or pair of chambers designed to hold film and move motion picture film stock before and after it has been exposed in the camera. In most movie cameras, the magazine is a removable piece of equipment.
Many still photo cameras also have removable camera magazines. A film cartridge serves the same function, but is usually not reusable.
A film holder is a device that holds one or more pieces of photographic film, for insertion into a camera or optical scanning device such as a dedicated film scanner or a flatbed scanner with film scanning capabilities. The widest use of the term refers to a device that holds sheet film for use in large format cameras, but it can also refer to various interchangeable devices in medium format or even 135 film camera systems.
Photographic film is a strip or sheet of transparent plastic film base coated on one side with a gelatin emulsion containing microscopically small light-sensitive silver halide crystals. The sizes and other characteristics of the crystals determine the sensitivity, contrast and resolution of the film.
The Reisekamera, meaning a "travel camera", is a large-format wooden bellows tailboard view camera of almost standardised design, unlike the much lighter and more flexible field camera, but not as cumbersome as the studio camera. A sturdy tripod is always brought along, but it might just as well be placed on a tabletop. It has equally sized rectangular front and back panels on a full-width double-extension baseboard that is hinged near the front. The front panel, holding the lens plate, has horizontal and vertical movements, while the back is tilt-suspended on brass standards running on brass tracks on either side of the baseboard, providing rack and pinion focusing on the film plane. An almost non-tapering calico double-extension bellows is employed; allowing the projected image to freely reach the photographic plate regardless of lens offset position. The camera folds flat, after the back panel is brought forward to the lens panel, by folding the hinged base board up, and thus conveniently protecting the focusing screen. For insertion of the wooden dark slide plate cassette, the hinged focusing screen is swung up and away. The Reisekamera was made available for several plate sizes; most common are the 13×18 cm, 18×24 cm and 24×30 cm versions. Shutter and lens were normally not part of the original delivery. However, some were made available with a spectacular focal-plane shutter, recognisable by the brass mechanisms either side of the back panel.
A contact copier, is a device used to copy an image by illuminating a film negative with the image in direct contact with a photosensitive surface. The more common processes are negative, where clear areas in the original produce an opaque or hardened photosensitive surface, but positive processes are available. The light source is usually an actínic bulb internal or external to the device
