ACID-FREE PAPER
Paper made from pulp containing little or no acid so it resists deterioration from age. Also called alkaline paper, archival paper, neutral pH paper, permanent paper and thesis paper.

ALBUMEM PRINT
The albumen print, also called albumen silver print, was invented in 1850 by Louis Désiré Blanquart-Evrard, and was the first commercially exploitable method of producing a photographic print on a paper base from a negative. It used the albumen found in egg whites to bind the photographic chemicals to the paper and became the dominant form of photographic positives from 1855 to the turn of the century, with a peak in the 1860-90 period. During the mid-1800s, the carte de visite became one of the more popular uses of the albumen method. In the 19th century, E. & H. T. Anthony & Company were the largest makers and distributors of the Albumen photographic prints and paper in the United States.

AMBROTYPE
A collodion positive created by placing an underexposed, bleached glass collodion negative in front of a dark background, often cloth or lacquer, to give the image the appearance of a positive image. Patented in the United States in 1854 by James Ambrose Cutting. Popular 1850s-70s.

ARCHIVAL PIGMENT INK PRINT
A print in which a digital file is outputted from a computer to an inkjet printer using archival quality paper and the image is printed with archival inks, which are UV stable and have a longevity of about 70-100 years.

ASPECT RATIO
The relative sizes of the height and width of an image. Many different aspect ratios have and continue to be used in photography. In film photography, the 3:2 ratio became the most commonplace, as it was the native ratio of 135 films. The 4:3 ratio of 645 formats also saw alot of usage. Many film cameras used a 1:1 (square) ratio, exemplified by the popular 126-film format.

Almost all digital camera models today natively use the 4:3 ratio. There are few exceptions to this rule among compact cameras but the majority of dSLR cameras use 3:2 sensors. A small number of compact cameras have had 3:2, 16:9 and 5:4 aspect ratio sensors.

An assortment of aspect ratios is used with photographic prints. This means images are often cropped to fit.

BLACK AND WHITE FILM
Light-sensitive film that, when processed, produces a black and white, negative image. The resulting "negative" is projected onto light-sensitive paper to make black and white photographic prints.

BROMOIL
This process was introduced in 1907 by E.J. Wall and eventually replaced the gum bichromate process. Once an enlargement was made on silver gelatin bromide paper, it was bleached in a solution of potassium bichromate to remove the black silver image. Then special brushes were used to apply greasy inks to pigment the surface of the gelatin.

CALOTYPE
The earliest paper negative process, invented by William Henry Fox Talbot in 1840 and patented in 1841. The paper is treated with a silver nitrate and potassium iodide solution. After the paper is dried it is then sensitized using a new solution of silver nitrate, gallic acid and acetic acid. After the paper is exposed in the camera it is then fixed in a solution of potassium bromide, or 'hypo.' Often times the paper is then waxed to create a translucency. These paper negatives are used to make salted paper photographs. Popular 1840s-50s.

CARBON PRINT
A pigment print is made by coating the paper with a layer of bichromated gelatin mixed with a carbon pigment. The paper is placed in direct contact with the negative and then exposed to light. The gelatin hardens according to how much light it receives. After exposure the paper is then put in contact with a fresh sheet of gelatin coated paper and then washed in a warm bath. During the bath the original sheet of paper floats free and the unhardened gelatin is removed. The remaining gelatin creates a relief transfer to the second sheet of paper. This process is very similar to the Woodburytype. Popular 1870s-80s; Revived 1910s-30s.

CHROMOGENIC PRINT (C-PRINT)
Also known as a "dye coupler print," this process was developed in the 1930's. Colored dyes are put on the emulsion in multiple layers and are sensitized to different wavelengths of light. During development, the silver image is bleached out, leaving only the dye image. This type of print uses Type-C paper.

CIBACHROME
Ilfochrome, (formerly known as Cibachrome) is a dye destruction positive-to-positive photographic process used for the reproduction of slides on photographic paper. The prints are made on a dimensionally stable tri-acetate polyester base, essentially a plastic base opposed to traditional paper base. Since it uses azo dyes on a polyester base, the print will not fade, discolor, or deteriorate for a long time. Characteristics of Ilfochrome prints are image clarity, color purity, more environmentally safe, as well as being an archival process able to produce critical accuracy to the original slide.

CINEMATOGRAPH
The cinematograph is a film camera, which also serves as a film projector and developer. It was invented in the 1890s.There is much dispute as to the identity of its inventor. Some argue that the device was first invented and patented as "Cinématographe Léon Bouly" by French inventor Léon Bouly in February 12, 1892. It is said that, due to a lack of fee, Bouly was not able to pay the rent for his patent the following year, and Auguste and Louis Lumière's engineers bought the license. Popular thought, however, dictates that Louis Lumière was the first to conceptualise the idea, and both Lumière brothers shared the patent. They made their first film, Sortie de l'usine Lumière de Lyon, in 1894. The film was publicly screened at L'Eden, the world's first and oldest cinéma, located in La Ciotat in southeastern France, on September 28, 1895. The first commercial, public screening of cinematographic films happened in Paris on 28 December 1895 and was organised by the Lumière brothers.

COLLODION NEGATIVE
A sheet of glass hand-coated with a thin film of collodion (guncotton dissolved in ether). This contains potassium iodide and is sensitised on location with silver nitrate. For maximum sensitivity, the plate had to be exposed while still wet and developed immediately. Introduced in 1851 by F. Scott Archer, the process gave a high resolution of detail. Dry collodion negatives, introduced later, were made by covering the collodion with a layer of albumen or gelatin.

COLLOTYPE
The collotype process was used between about 1870 and 1920. A glass plate was coated with sensitised gelatin and exposed under a negative. Light passed through the negative would harden the gelatin on the glass plate. The unexposed gelatin would absorb the water when washed and the exposed would repel it. The washed glass plate would be coated with ink, adhering to the exposed gelatin and printed onto fine paper.

CONTACT PRINT
A contact print is a photographic image produced from a film, usually a negative, occasionally from a film positive. The defining characteristic of a contact print is that the photographic result is made by exposing through the film original onto a light sensitive material pressed tightly to the film.

COLOR CARBON TRANSFER PRINT
Carbon printing has always been the most difficult but also the most beautiful of all photo printing processes. The first color print affixed to paper was made in 1868 by Louis Ducos du Hauron using the carbon process. Color carbon transfer printing is an assembly process where the original transparency is separated into negatives that contain the information for each color layer. Each separation negative is contact printed to the appropriate dichromated pigment saturated gelatin film made with cyan, magenta, yellow and black light-fast pigments. The action of ultraviolet light on dichromated gelatin colloid renders the gelatin insoluble. When developed in hot water, the unexposed gelatin washes away leaving a relief image. In exact registration, these reliefs are mounted one on top of the other onto a temporary support and then transferred to gelatin-coated fine art paper.

Because the carbon printing process uses pigments instead of dyes, it is more archivally stable than any of the other color processes and has the longest tonal scale, highest resolution, and largest color palette giving the prints rich color reproduction and subtly nuanced tone transitions. If light-fast pigments are used, carbon transfer prints are truly permanent prints that can be expected to remain unchanged for centuries.

CYANOTYPE
An early printing-out process invented in 1842 by Sir John Herschel. The paper is coated with ferric salt and potassium ferricyanide and is put in direct contact with the negative to create an image. When exposed to light the areas not covered by dark imagery or objects became a bright blue color. The paper is then washed in warm water to fix the image. Popular 1850s-1900.

DAGUERREOTYPE
Introduced to the world in 1839 by Louis-Jacques Mandé Daguerre and reputed to be the first photographic process. Daguerreotypes are unique images on a silver coated copper plate. The copper plate is cleaned and polished and sensitized with iodine vapor. After the plate is exposed in the camera it is then developed with mercury vapor and fixed by washing in a salt solution. The images are direct positives and no negative is required. The surface of the plate is very sensitive after fixing and the plates are displayed with a glass covering to protect the image. Other direct positive processes are Ambrotypes and Tintypes. Popular 1840-50s.

DEPTH OF FIELD (DOF)
The distance between the farthest and nearest points which are in focus. "Depth-of-field" can also be used to describe the zone of acceptable sharpness before and behind a given focused subject. DOF varies according to numerous factors such as lens focal length, aperture, shooting distance, etc.

DIGITAL C-PRINT
A chromogenic print made by exposing Type-C photographic paper (such as Fuji Crystal Archive) with a digital enlarger instead of projected light by a traditional enlarger. The digital C-print is then processed in a color processor, or a wet darkroom process, just as a traditional C-print would be.

DIGITAL IMAGE
Digital images are created using a gridded mosaic of light sensitive picture elements, called pixels, embedded on a computer chip. The pixels emit electrical signals in proportion to the amount of light they receive and these signals are converted to numbers and then stored electromagnetically - in a computer or on a disc, for example. Digital images can be manipulated and altered by computer and regenerated in many ways: on computer or television screens, on film, printed or projected. The technology for producing digital images is evolving rapidly with new possibilities constantly emerging.

DIGITAL PROOF
This is a proofing system that does not include the use of film. Data is sent to a printer and imaged directly onto a paper-based material. There are several limitations of a digital proof: 1) they do not use the film that will be used to produce plates, and thus are open to interpretation of the output device, 2) few of these devices print in the same dot pattern as is utilized in the printing process, and 3) the ink utilized in these printers is not representative of the inks used in the printing process and can show a vast colour range and density not attainable on a printing press. Digital proofs are usually used where money or time is too much of an issue to run a wet proof.

DYE DESTRUCTION PRINT / CIBACHROME/ILFOCHROME
Dye destruction prints are made using print material which has at least three emulsion layers, each one sensitised to a different primary colour - red, blue or green - and each one containing a dye related to that colour. During exposure to a colour transparency, each layer records different information about the colour make-up of the image. During printing, the dyes are destroyed or preserved to form a full colour image in which the three emulsion layers are perceived as one. Dye destruction prints are characterised by vibrant colour. The process used to be called Cibachrome: it is now known as Ilfochrome.

DYE TRANSFER PRINT
"In this method of color printing, an original transparency or negative is projected or contact printed on to three separate sheets of film through red, green and blue filters. These separation negatives are then projected or contact printed to make three relief matrices dyed in cyan, magenta and yellow dyes. Each of the matrices is then brought into registered contact with a sheet of special dye-transfer paper which absorbs the dye. The finished print is therefore made up of a combination of dye images. Dye-transfer is one of the most permanent color processes. However, the film was discontinued in 1996." (An excerpt from AIPAD's brochure "On Collecting Photographs".)

FUJIFLEX
Fuji-made chromogenic color paper (C-print) which is extremely glossy, similar to an Ilfochrome or Cibachrome: A process by which a photographic print is made directly from a color transparency. Although still widely used, the Cibachrome name was changed to Ilfochrome over a decade ago. This process's qualities include rich color, clarity and unprecedented archival quality for color prints. Cibachrome (now Ilfochrome) is the trade name originally given to this printing process by Ilford/Ciba-Geigy in the 1950s. This type of print uses Type-R paper.

GELATIN-SILVER PRINT
The gelatin-silver process is the photographic process used with currently available black-and-white films and printing papers. A suspension of silver salts in gelatin is coated onto acetate film or fiber-based or resin coated paper and allowed to dry (hence the term dry plate). These materials remain stable for months and years unlike the 'wet plate' materials that preceded them.

GELATIN-SILVER PRINT ON VELLUM
Gelatin Silver Print on Vellum print is a term that Mark Citret uses to differentiate the type of print he chose to work in from conventional gelatin silver prints. In 1991 he began printing on a unique and obscure paper that Kodak had manufactured for many years called "Polyfiber A". The "A" designated a paper of extreme light-weight and vellum-like surface. Citret derived a toning procedure that yields warmth to a far greater degree in the highlight areas than other toning. This toning procedure, in combination with the paper used, is where Citret derived the term, Vellum Prints.

GICLEE
Giclée is an invented name for the process of making fine art prints from a digital source using ink-jet printing. The word "giclée", from the French language word "le gicleur" meaning "nozzle", or more specifically "gicler" meaning "to squirt, spurt, or spray" It was coined by Jack Duganne, a printmaker working in the field, to represent any inkjet-based digital print used as fine art. The intent of that name was to distinguish commonly known industrial "Iris proofs" from the type of fine art prints artists were producing on those same types of printers. The name was originally applied to fine art prints created on Iris printers in a process invented in the early 1990s but has since come to mean any high quality ink-jet print and is often used in galleries and print shops to denote such prints.

GLASS NEGATIVE
In 1851, Frederick Scoff Archer, an English sculptor, invented the wet plate. Using a viscous solution of collodion, he coated glass with light-sensitive silver salts. Because it was glass and not paper, this wet plate created a more stable and detailed negative.

GUM BICHROMATE PRINT
A process introduced in 1894 which produced color tones, almost painterly like, by printing on any type of paper coated with layer(s) of sensitized and pigmented gum arabic.

GUM DICHROMATE PRINT
In the three color gum dichromate process, a sheet of watercolor paper is repeatedly coated with a sensitizer (gum arabic, a potassium dichromate solution to make it light sensitive and a watercolor pigment), exposed through the relevant negative (separation) and processed. The image is built up in three successive printings, one for each of the process colors of yellow, magenta and cyan although this order can vary between printers.

The three parts of the sensitizer are mixed together and painted by brush onto the paper. A thicker mixture containing a higher proportion of pigment and having a short exposure time will place the color primarily in the shadow areas, whereas a thinner mixture with less pigment and a longer exposure will give color mainly to the highlights and lighter tones. So some contrast control is possible in the printing.

Immediately the coated paper has dried, it¹s exposed in contact with the corresponding separation to ultraviolet light. A registration system is crucial to ensure that the negatives are positioned correctly for each printing.

HAND COLORED TONED CYANOTYPE
An early printing-out process invented in 1842 by Sir John Herschel. The paper is coated with ferric salt and potassium ferricyanide and is put in direct contact with the negative to create an image. When exposed to light the areas not covered by dark imagery or objects became a bright blue color. The paper is then washed in warm water to fix the image. Popular 1850s-1900.

HAND-COLORED CYANOTYPE
A cyanotype that has the addition of colored pencil.

HAND PAINTED GELATIN SILVER PRINT
Handpainting of photographs has been done since the beginning of photography and is mostly done on gelatin silver images using oil paints or color pencils, although this process can be done on other mediums including platinum prints.

HASSELBLAD CAMERA
Victor Hasselblad AB is a Swedish manufacturer of medium-format cameras and photographic equipment based in Gothenburg, Sweden. The company is best known for the medium-format cameras it has produced since World War II.

Perhaps the most famous use of the Hasselblad camera was during the Apollo Program missions when man first landed on the Moon. Almost all of the still photographs taken during these missions used specially modified Hasselblad cameras.

Hasselblad's traditional V-System cameras are still widely used by professional and serious amateur photographers. One reason is a reputation for long service life and quality of available lenses.

ILFOCHROME PRINT
Contemporary term for Cibachrome print - A process by which a photographic print is made directly from a color transparency. Although still widely used, the Cibachrome name was changed to Ilfochrome over a decade ago. This process's qualities include rich color, clarity and unprecedented archival quality for color prints. Cibachrome (now Ilfochrome) is the trade name originally given to this printing process by Ilford/Ciba-Geigy in the 1950s. This type of print uses Type-R paper.

INSTAMATIC
The Instamatic was a series of inexpensive, easy-to-load 126 and 110 cameras made by Kodak beginning in 1963. The Instamatic was immensely successful, introducing a generation to low-cost photography and spawning numerous imitators. During its heyday, the range was so ubiquitous that the Instamatic name is still frequently used (erroneously) to refer to any inexpensive point and shoot camera. (It is also frequently used incorrectly to describe Kodak's line of instant-picture cameras.)

INSTANT FILM
A kind of film equipped for chemical self-development of each single image that is triggered by the instant camera after exposure. Dr. Edwin H. Land the Polaroid Corporation produced the first instant film and cameras in 1948. Instant film has been made by Fuji, Kodak, Polaroid.

IRIS PRINT
Iris printing is a specific form of Giclee printing. Giclee is a French term, loosely translated "to spray" which is an appropriate description of the Iris printing method. The Iris is a large cylindrical drum based inkjet printer made up of a complex array of mechanics which squirt minute droplets of ink from each of its four nozzles (Cyan, Magenta, Yellow and Black). The term "Giclee" was created to differentiate a commercial standard from the work of a fine art print and "Iris print" to differentiate other Giclee prints from prints specifically made with an Iris printer.

KALLITYPE
Developed in 1842 in England, this process uses a base sensitizer of iron salts and silver nitrate, then is combined with water and coated on paper. Then objects are placed on the paper and exposed to UV light, like a photogram or sunprint. The image is then developed and fixed. The result is a one-of-a-kind print. Similar processes are Van Dyke prints and Cyanotypes.

KINETOSCOPE
The Kinetoscope is an early motion picture exhibition device. Though not a movie projector—it was designed for films to be viewed individually through the window of a cabinet housing its components—the Kinetoscope introduced the basic approach that would become the standard for all cinematic projection before the advent of video: it creates the illusion of movement by conveying a strip of perforated film bearing sequential images over a light source with a high-speed shutter. First described in conceptual terms by U.S. inventor Thomas Edison in 1888, it was largely developed by his employee William Kennedy Laurie Dickson between 1889 and 1892. Dickson and his team at the Edison lab also devised the Kinetograph, an innovative motion picture camera with rapid intermittent, or stop-and-go, film movement, to photograph movies for in-house experiments and, eventually, commercial Kinetoscope presentations.

KODACHROME
Kodachrome is the trademarked brand name of a type of color reversal film that was manufactured by Eastman Kodak from 1935 to 2009. Kodachrome was the first successfully mass-marketed color still film using a subtractive method, in contrast to earlier additive "screenplate" methods such as Autochrome and Dufaycolor, and remained the oldest brand of color film.

LAMBDA C-TYPE PRINT
A print made from a 'Lightjet' laser printer that reads a digital file, then uses red, green and blue lasers to expose the image onto Type C (light sensitive) photographic paper. The paper is then processed in RA-4 chemistry, a wet darkroom process.

LANTERN SLIDE OR GLASS PLATE
The practice of projecting images from glass plates began centuries before the invention of photography. As early as the seventeenth century the Magic Lantern, or Sciopticon, was used to project painted images on glass for children’s picture shows and for religious displays. In the 1840s, Philadelphia daguerreotypists, William and Frederick Langenheim, began experimenting with The Magic Lantern as an apparatus for displaying their photographic images. By using that negative to print onto another sheet of glass rather than onto paper, the Langenheims were able to create a transparent positive image, suitable for projection. The brothers patented their invention in 1850 and called it a Hyalotype.

LARGE FORMAT
Large format refers to the type of camera and film in which sheets of film are sized 4x5", 5x7", 8x10" and higher, rather than using rolls of film. Because the negatives are so large, they do not need as much enlarging as a smaller negative therefore creating an image of the highest quality and least grain. Large format cameras are often referred to as view cameras. Commonly, contact prints are made from the negatives.

LIGHTJET
LightJet is a trademark of Océ Display Graphics Systems, a division of Océ N.V. (the company that acquired Cymbolic Sciences, Inc.) for a process of printing digital images to photographic paper and film, and for the corresponding hardware. Ordinary silver-covered photographic paper is fixed on an internal drum, where three lasers simultaneously expose the paper (or Duratrans) with red, green, and blue light. The print is then processed using traditional photochemical means.

LIMITED EDITION
Set by the photographer, a limited edition is the stated number of prints reproduced of an individual photograph in all available sizes and formats. Once this edition has been set, the photographer does not / can not produce any further prints in that stated edition of this particular print.

MEDIUM FORMAT
A film size between small (35mm) and large format (4x5" or 8x10"). The rolls of film, sold as 120 (for 10 exposures) and 220 (for 20 exposures), are 6cm wide and can generate an image space of 6x6cm, 4.5x6cm, 6x7cm, 6x9cm and 6x17cm panoramic. Square format is commonly referred to as 2 1/4 (for inches) and is produced by such cameras as the Hasselblad.

MIXED MEDIA
Art work created by more than one visual art medium. Usually a combination of one or more of the following: paint, photography, ink, pencil, collage, encaustic, sculpture, etc.

MORDANÇAGE PRINT
Mordançage is a process whereby the artist strips away the darkest parts of the emulsion of a silver gelatin print. The stripping away of the emulsion is the most important stage of the process - the image transformation, creating a relief, or a raised area on the print. Water is used to float the delicate silver emulsion on the image so as to rearrange it and dry it back down on to the print. The end result is a one of a kind and unique photographic image.

MUSEUM-QUALITY
High-quality image output for reproductions and photo enlargements.

OROTONE
A photographic process made popular by Edward S. Curtis in the early 1900s. A glass plate coated with a gelatin silver emulsion is exposed to a negative. After the plate is exposed and developed the back of the plate is painted gold, creating a positive image. Popular 1890s-1920s.

PANCHROMATIC
Photo material that is sensitive to all colors that the human eye can perceive.

PANORAMIC
In photography, an image proportionally more rectangular than a 35mm film frame. Also, a type of camera for exposing film in a panoramic format.

PHOTOGENIC DRAWING
Photogenic drawing was William Henry Fox Talbot’s name for the results of his first cameraless photographic process which he announced in 1839. In its simplest form a smooth high quality sheet of writing paper was immersed in a solution of table salt and then dried. Talbot brushed the paper with a solution of silver nitrate. This combined with the salt to produce silver chloride which is light sensitive. Small objects such as leaves and lace could then be placed on the paper and exposed to sunlight. This produced a light image of the object against a dark background; in other words, a negative image.

PHOTOGRAM
A cameraless, lensless, unique image made by placing objects on a photo-sensitive surface, then exposing to light. The object is removed and the paper processed. The paper stays light where the object was placed, and the rest of the paper darkens. First made by William Henry Fox Talbot in England in 1834, and later revived by such artists as Lazlo Moholy-Nagy and Man Ray. Adam Fuss is perhaps the most well-known contemporary artist using this process.

PHOTOGRAVURE
Photogravure is a process for reproducing a photograph in large editions. It uses gelatin to transfer the image from a black and white negative to a copper printing plate. The gelatin carries the image because it hardens in proportion to its exposure to light. Areas of the gelatin not exposed stay soft and can be dissolved away in water. What remains is a gelatin version of the image which is then pressed onto a copper plate. The plate is placed in an acid bath. Where the gelatin is thick, the acid eats the metal away slowly, where the gelatin is thin or absent, the acid eats faster. Thus the plate is etched to different depths according to the tones of the original image. When inked for printing, the varying depths hold different amounts of ink.

PINHOLE CAMERA
The most basic form of a camera in which no lens is used. A pinhole camera is made by making a lightight container and poking a pinhole in the front of the camera where a lens would go. Light that enters this hole exposes photosensitive material, which is placed on the backside of the interior of the camera. Because the pinhole is so small, exposures made with this type of camera tend to be longer than on a regular camera and the depth of field of the image tends to be nearly infinite, although the edges tend to be soft due to diffraction.

PLATINUM
The most permanent photographic process. The platinum print is made by sensitizing a sheet of paper with iron and platinum salts. After exposure the paper is then washed with a potassium oxalate solution, which creates a photographic print with a great range of gray tones. Popular 1890s-present.

PLATINUM/PALLADIUM PRINT
The Platinum print image is made from finely particulate grains of platinum metal by a process invented by William Willis in the late 19th century. A photographer could purchase the ready-made platinum paper for use at that time. Today the modern platinum printer hand-coats the emulsion onto a good rag stock paper and exposes under ultraviolet light (the sun or a UV exposure unit). The resulting print is a warm black hue and virtually impervious to fading and bleaching from age or atmospheric pollutants.

POLAROID
An instant film, giving an almost immediate positive print.

POLAROID INSTANT CAMERA
The instant camera is a type of camera with self-developing film. The best known are those formerly made by Polaroid Corporation.The invention of modern instant cameras is generally credited to American scientist Edwin Land, who unveiled the first commercial instant camera, the Land Camera, in 1947, 10 years after founding Polaroid Corporation.

POLYMERGRAVURE
A black and white image is laid on top of a steel plate which has been coated with a photo-sensitive emulsion and then it is exposed to UV light, causing the image to be etched onto the plate. A printer's ink is rubbed into the etched image, and then the plate is run through an etching press to transfer the image to paper.

PHYSICAL PROOF
Printed picture reproduction for approving color and printing enlargement resolution.

RAPATRONIC CAMERA
The rapatronic camera is a high-speed camera capable of recording a still image with an exposure time as brief as 10 nanoseconds (billionths of a second).The camera was developed by Harold Edgerton in the 1940s and was first used to photograph the rapidly-changing matter in nuclear explosions within milliseconds of ignition.[1] To overcome the speed limitation of a conventional camera's mechanical shutter, the rapatronic camera uses two polarizing filters and a Kerr cell. The two filters are mounted with their polarization angles at 90° to each other, to block all incoming light. The Kerr cell between the filters, which changes the polarization of light passing through it when energized, acts as shutter when it is energized at the right time for a very short amount of time, allowing the film to be properly exposed.

REAL PHOTO POSTCARDS
In 1903 Kodak introduced the No. 3A Folding Pocket Kodak. The camera, designed for postcard-size film, allowed the general public to take photographs and have them printed on postcard backs. They are usually the same size as standard vintage postcards (3-1/2" x 5-1/2"). Also known by the acronym "RPPC".

REVERSED CYANOTYPE PHOTOGRAM
A photogram is made in the darkroom on film. The resulting negative is then placed on prepared paper and exposed as a cyanotype. This results in the usual cyanotype tones (blue and white), however they reversed. These are only somewhat repeatable, because of the negative, but no two look the same.

SALTED PAPER PRINT
Invented in 1840, these were the earliest photographic prints on paper. The photographs are made as contact prints using calotype negatives. The paper is treated with light-sensitive silver chloride salts and exposed to light. The prints are then fixed in a salt solution and later in a solution of potassium bromide or sodium thiosulphate. Popular 1840s-50s.

SELENIUM TONED PRINT
A black and white gelatin silver print in which a chemical solution containing selenium is used to tone or "hue" the overall image. This type of toning is used for extending the archival qualities of the print making it less subjected to atmospheric pollutants. If toned for a short period of time, it gives a "warmer" feel to the overall print, making the cold tone of general black and whites turn ever the slightest bit more brownish-purple. If toned for a longer period of time, the color of the blacks can change to an eggplant hue.

SEPIA TONE
Sepia tone refers to the coloring of a black and white photographic print that has been toned with a sepia toner to simulate the faded brownish color of some early photographs.

STEREOVIEWS
Stereoscopy, stereoscopic imaging or 3-D (three-dimensional) imaging is any technique capable of recording three-dimensional visual information or creating the illusion of depth in an image. The illusion of depth in a photograph, movie, or other two-dimensional image is created by presenting a slightly different image to each eye. Many 3D displays use this method to convey images. It was first invented by Sir Charles Wheatstone in 1840.

SOLAR PLATE ETCHING
A black and white image is laid on top of a steel plate which has been coated with a photo-sensitive emulsion and then it is exposed to UV light, causing the image to be etched onto the plate. A printer's ink is rubbed into the etched image, and then the plate is run through an etching press to transfer the image to paper.

SOLARIZED PRINT
The effect caused by fogging (exposing to light) an image that has been partially developed, in which white areas turn black and black areas turn white, in essence reversing the image to almost look like a negative instead of a typical positive.

TALBOTYPE
The earliest paper negative process, invented by William Henry Fox Talbot in 1840 and patented in 1841. The paper is treated with a silver nitrate and potassium iodide solution. After the paper is dried it is then sensitized using a new solution of silver nitrate, gallic acid and acetic acid. After the paper is exposed in the camera it is then fixed in a solution of potassium bromide, or 'hypo.' Often times the paper is then waxed to create a translucency. These paper negatives are used to make salted paper photographs. Popular 1840s-50s.

TINTYPE
This process is much like the ambrotype. It is a unique photograph on a sheet of iron that is coated with a dark enamel. The tintype, also known as the ferrotype, was essentially a collodion negative, which appeared positive when put against a dark background. The tintype became popular in the 1850s as a less expensive way to produce photographs for the masses. Popular 1860s-70s; Revived 1980s-Present.

TONED CYANOTYPE
An early printing-out process invented in 1842 by Sir John Herschel. The paper is coated with ferric salt and potassium ferricyanide and is put in direct contact with the negative to create an image. When exposed to light the areas not covered by dark imagery or objects became a bright blue color. The paper is then washed in warm water to fix the image. Popular 1850s-1900.

TONED GELATIN SILVER PRINT
A black and white gelatin silver print in which a chemical is used change the hue of the overall image to a shade of red, brown (sepia), green, blue or purple. Most toners extend the archival quality of the print by making it more stable.

UNION CASE
"Union Case" and is an example of an early thermoplastic technology, being produced from about 1855 to 1865. Some people call them gutta-percha cases but that is not a correct term, better being "thermoplastic case" or, as we use, a "Union Case". Littlefield, Parsons & Co. was one such case manufacturers. A mixture of shellac and wood fibers were pressed into a steel mold. And to think we thought "plastics" were new in the 1950s, look at the quality they achieved in the 1850s!

WOODBURYTYPE
The Woodburytype was a form of photomechanical reproduction of a photograph patented in 1864 by Walter Bentley Woodbury. Despite the painstaking care required, it remained popular until about 1900 because of the very high quality of the final image. This image was formed in pigmented gelatin rather than ink, with thicker or thinner areas of gelatin giving darker or lighter tone. The result was a reproduced image that was very true to the original and highly luminous.

35MM
A small format film, with an image size of 24 x 36mm available in 12, 24 or 36 exposures. It is the most commonly used film size, but does not offer the quality of medium or large format, because this small negative must be enlarged quite a bit in the darkroom loosing it's clarity and sharpness.