|
Kallitype
Kallitype is a process for making photographic prints. Patented in 1889 by W. W. J. Nicol (1855-1929), the Kallitype print is an iron-silver process. A chemical process similar to the Van Dyke brown based on the use of a combination of ferric and silver salts. While Van Dyke brown and argyrotype use ferric ammonium citrate, the light-sensitive element used for the Kallitype is ferric oxalate. The use of ferric oxalate allows for both extended shadow definition (higher DMAX) and contrast control. Many developing solutions can be used to give a different image color (brown, sepia, blue, maroon and black). Kallitype images generally have a richer tonal range than the cyanotype. These prints were popular in the 19th century, and then their popularity faded away. Sometimes known as "the poor man's platinum print", when the image is toned in platinum or palladium the result is nearly chemically identical to a true Platinotype. It is believed that many Kallitypes were passed off as true ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kallitype Test Print Zev Schmitz
Kallitype is a process for making photographic prints. Patented in 1889 by W. W. J. Nicol (1855-1929), the Kallitype print is an iron-silver process. A chemical process similar to the Van Dyke brown based on the use of a combination of ferric and silver salts. While Van Dyke brown and argyrotype use ferric ammonium citrate, the light-sensitive element used for the Kallitype is ferric oxalate. The use of ferric oxalate allows for both extended shadow definition (higher DMAX) and contrast control. Many developing solutions can be used to give a different image color (brown, sepia, blue, maroon and black). Kallitype images generally have a richer tonal range than the cyanotype. These prints were popular in the 19th century, and then their popularity faded away. Sometimes known as "the poor man's platinum print", when the image is toned in platinum or palladium the result is nearly chemically identical to a true Platinotype. It is believed that many Kallitypes were passed off as true ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Argyrotype
Argyrotype is an iron-based silver printing process that produces brown images on plain paper. It is an alternative process derived from the argentotype, kallitype, and Van Dyke processes of the 19th century, but has greater simplicity, improved image stability, and longer sensitizer shelf-life.Mike Ware It was developed by Mike Ware. While this process may not have the permanence of other processes such as platinum or palladium printing, it is much less expensive and more user friendly. The core resource used is silver sulphamate (NH2SO3Ag) which can be prepared on site from sulphamic acid. The sensitizer used is very slow, so printing must be by contact with a large format negative, using an ultraviolet Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nanometer, nm (with a corresponding frequency around 30 Hertz, PHz) to 400 nm (750 Hertz, THz), shorter than that of visible light, but longer than ... lamp or sunlight. As w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Van Dyke Brown (printing)
Van Dyke brown is a printing process named after Anthony van Dyck. It involves coating a canvas with ferric ammonium citrate, tartaric acid, and silver nitrate, then exposing it to ultraviolet light. The canvas can be washed with water, and hypo to keep the solutions in place. The image created has a Van Dyke brown color when it's completed, and unlike other printing methods, does not require a darkroom. The Van Dyke brown process was patented in Germany in 1895 by Arndt and Troost. It was originally called many different names, such as sepia print or brown print. It has even been called kallitype, however that process uses ferric oxalate Ferric oxalate, also known as iron(III) oxalate, is a chemical compound composed of ferric ions and oxalate ligands; it may also be regarded as the ferric salt of oxalic acid. The anhydrous material is pale yellow; however, it may be hydrated to f ... instead of ferric ammonium citrate. Concerns have been voiced about the archival qualiti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxalic Acid
Oxalic acid is an organic acid with the systematic name ethanedioic acid and formula . It is the simplest dicarboxylic acid. It is a white crystalline solid that forms a colorless solution in water. Its name comes from the fact that early investigators isolated oxalic acid from flowering plants of the genus ''Oxalis'', commonly known as wood-sorrels. It occurs naturally in many foods. Excessive ingestion of oxalic acid or prolonged skin contact can be dangerous. Oxalic acid has much greater acid strength than acetic acid. It is a reducing agent and its conjugate base, known as oxalate (), is a chelating agent for metal cations. Typically, oxalic acid occurs as the dihydrate with the formula . History The preparation of salts of oxalic acid (crab acid) from plants had been known, at least since 1745, when the Dutch botanist and physician Herman Boerhaave isolated a salt from wood sorrel. By 1773, François Pierre Savary of Fribourg, Switzerland had isolated oxalic acid from i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Negative (transparency)
The digital negative is the collective name for methods used by photographers to create negatives on transparency film for the contact printing of alternative photographic techniques. The negatives can also be enlarged using traditional gelatin silver processes, though this is usually reserved for negatives of 4x5" or larger due to quality limitations imposed by printer technology. This set of techniques is separate from the Digital negative (DNG) file format, although this format may be used to create digital negative transparencies. Uses Digital negatives are typically used with one of the alternative processes such as gum bichromate, cyanotype, or Inkodye. In these cases digital negatives are most commonly printed full size to create contact prints. The negative is sandwiched printer ink-to-emulsion in a contact printing frame and exposed under a UV light source. They can also be used to create positives (where the initial digital file is not inverted) to make positives on e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Darkroom
A darkroom is used to process photographic film, to make prints and to 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. Darkrooms have been used since the inception of photography in the early 19th century. Darkrooms have many various manifestations, from the elaborate space used by Ansel Adams to a retooled ambulance wagon used by Timothy H. O'Sullivan. From the initial development of the film to the creation of prints, the darkroom process allows complete control over the medium. Due to the popularity of color photography and complexity of processing color film (''see C-41 process'') and printing color photographs and also to the rise, first of instant photography technology and later digital photography, darkrooms are dec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Large Format (photography)
Large format refers to any imaging format of or larger. Large format is larger than "medium format", the or size of Hasselblad, Mamiya, Rollei, Kowa, and Pentax cameras (using 120- and 220-roll film), and much larger than the frame of 35 mm format. The main advantage of a large format, film or digital, is a higher resolution at the same pixel pitch, or the same resolution with larger pixels or grains which allows each pixel to capture more light enabling exceptional low-light capture. A 4×5 inch image (12.903 mm²) has about 15 times the area, and thus 15× the total resolution, of a 35 mm frame (864 mm²). Large format cameras were some of the earliest photographic devices, and before enlargers were common, it was normal to just make 1:1 contact prints from a 4×5, 5×7, or 8×10-inch negative. Formats The most common large format is 4×5 inches (10.2x12.7 cm), which was the size used by cameras like the Graflex Speed Graphic and Crown Gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contact Printing
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 film or photographic 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. The defining characteristic of a contact print is that the resulting print is the same size as the original, rather than having been projected through an enlarger. Basic tools Contact printing is a simple and inexpensive process. Its simplicity avails itself to those who may want to try darkroom processing without buying an enlarger. One or more negatives are placed on a sheet of photographic paper which is briefly exposed to a light source. The light may come from a low wattage frosted bulb hanging above an easel which holds them together, or contained in an exposure ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyanotype
The cyanotype (from Ancient Greek κυάνεος - ''kuáneos'', “dark blue” + τύπος - ''túpos'', “mark, impression, type”) is a slow-reacting, economical photographic printing formulation sensitive to a limited near ultraviolet and blue light spectrum, the range 300 nm to 400 nm known as UVA radiation. It produces a cyan-blue print used for art as monochrome imagery applicable on a range of supports, and for reprography in the form of blueprints. For any purpose, the process usually uses two chemicals: ferric ammonium citrate or ferric ammonium oxalate, and potassium ferricyanide, and only water to develop and fix. Announced in 1842, it is still in use. History The cyanotype was discovered, and named thus, by Sir John Herschel who in 1842 published his investigation of light on iron compounds, expecting that photochemical reactions would reveal, in form visible to the human eye, the infrared extreme of the electromagnetic spectrum detected by his ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platinotypes
Platinum prints, also called ''platinotypes'', are photographic prints made by a monochrome printing process involving platinum. Platinum tones range from warm black, to reddish brown, to expanded mid-tone grays that are unobtainable in silver prints. Unlike the silver print process, platinum lies on the paper surface, while silver lies in a gelatin or albumen emulsion that coats the paper. As a result, since no gelatin emulsion is used, the final platinum image is absolutely matte with a deposit of platinum (and/or palladium, its sister element which is also used in most platinum photographs) absorbed slightly into the paper. Platinum prints are the most durable of all photographic processes. The platinum group metals are very stable against chemical reactions that might degrade the print—even more stable than gold. It is estimated that a platinum image, properly made, can last thousands of years. Some of the desirable characteristics of a platinum print include: * The re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platinotype
Platinum prints, also called ''platinotypes'', are photographic prints made by a monochrome printing process involving platinum. Platinum tones range from warm black, to reddish brown, to expanded mid-tone grays that are unobtainable in silver prints. Unlike the silver print process, platinum lies on the paper surface, while silver lies in a gelatin or albumen emulsion that coats the paper. As a result, since no gelatin emulsion is used, the final platinum image is absolutely matte with a deposit of platinum (and/or palladium, its sister element which is also used in most platinum photographs) absorbed slightly into the paper. Platinum prints are the most durable of all photographic processes. The platinum group metals are very stable against chemical reactions that might degrade the print—even more stable than gold. It is estimated that a platinum image, properly made, can last thousands of years. Some of the desirable characteristics of a platinum print include: * The re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palladium
Palladium is a chemical element with the symbol Pd and atomic number 46. It is a rare and lustrous silvery-white metal discovered in 1803 by the English chemist William Hyde Wollaston. He named it after the asteroid Pallas, which was itself named after the epithet of the Greek goddess Athena, acquired by her when she slew Pallas. Palladium, platinum, rhodium, ruthenium, iridium and osmium form a group of elements referred to as the platinum group metals (PGMs). They have similar chemical properties, but palladium has the lowest melting point and is the least dense of them. More than half the supply of palladium and its congener platinum is used in catalytic converters, which convert as much as 90% of the harmful gases in automobile exhaust (hydrocarbons, carbon monoxide, and nitrogen dioxide) into nontoxic substances (nitrogen, carbon dioxide and water vapor). Palladium is also used in electronics, dentistry, medicine, hydrogen purification, chemical applications, groundwate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2.jpg "Click for more on -> Palladium")