An enlarger is a specialized transparency
projector
A projector or image projector is an optical device that projects an image (or moving images) onto a surface, commonly a projection screen. Most projectors create an image by shining a light through a small transparent lens, but some newer types ...
used to produce
photographic
Photography is the art, application, and practice of creating durable 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 ...
prints from film or glass
negatives, or from
transparencies.
Construction
All enlargers consist of a light source, normally an
incandescent light bulb
An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light with a wire filament heated until it glows. The filament is enclosed in a glass bulb with a vacuum or inert gas to protect the filament from oxida ...
shining though a
condenser or translucent screen to provide even illumination, a holder for the negative or transparency, and a specialized
lens
A lens is a transmissive optical device which focuses or disperses a light beam by means of refraction. A simple lens consists of a single piece of transparent material, while a compound lens consists of several simple lenses (''elements''), ...
for projection. The light passes through a
film
A film also called a movie, motion picture, moving picture, picture, photoplay or (slang) flick is a work of visual art that simulates experiences and otherwise communicates ideas, stories, perceptions, feelings, beauty, or atmosphere ...
holder, which holds the exposed and
developed photographic negative or transparency.
Prints made with an enlarger are called ''enlargements''. Typically, enlargers are used in a
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 ph ...
, an enclosed space from which extraneous light may be excluded; some commercial enlargers have an integral dark box so that they can be used in a light-filled room.
History
Josef Maria Eder
Josef Maria Eder (16 March 1855 – 18 October 1944) was an Austrian chemist who specialized in the chemistry of photography, and who wrote a comprehensive early history of the technical development of chemical photography.
Life and work
Eder was ...
, in his ''History of Photography'' attributes the invention of photographic enlargement to
Humphry Davy
Sir Humphry Davy, 1st Baronet, (17 December 177829 May 1829) was a British chemist and inventor who invented the Davy lamp and a very early form of arc lamp. He is also remembered for isolating, by using electricity, several elements for t ...
who realised the idea of using a solar microscope to project images onto sensitised paper. In June 1802 Davy published in the first issue of the ''Journals of the Royal Institution of Great Britain'' his ''An Account of a Method of Copying Paintings upon Glass, and of Making Profiles, by the Agency of Light upon Nitrate of Silver. Invented by T. Wedgwood, Esq. With Observations by H. Davy'' in which he described their experiments with the photosensitivity of silver nitrate. Eder credits the first mention of enlargements after the announcement of the
daguerreotype
Daguerreotype (; french: daguerréotype) was the first publicly available photographic process; it was widely used during the 1840s and 1850s. "Daguerreotype" also refers to an image created through this process.
Invented by Louis Daguerre an ...
(unique images on metal plates) to
John William Draper
John William Draper (May 5, 1811 – January 4, 1882) was an English-born American scientist, philosopher, physician, chemist, historian and photographer. He is credited with producing the first clear photograph of a female face (1839–40) and ...
who in 1840, during, wrote prophetically in the ''American Repository of Arts''; "Exposures are made with a very small camera on very small plates. These are subsequently enlarged to the required size in a larger camera on a rigid stand. This method will probably contribute very much to the practice of the art" In March 1843 Americans
Wolcott and
Johnson
Johnson is a surname of Anglo-Norman origin meaning "Son of John". It is the second most common in the United States and 154th most common in the world. As a common family name in Scotland, Johnson is occasionally a variation of ''Johnston'', a ...
patented a means of copying and enlarging daguerreotypes.
In June 1843
Henry Fox Talbot
William Henry Fox Talbot FRS FRSE FRAS (; 11 February 180017 September 1877) was an English scientist, inventor, and photography pioneer who invented the salted paper and calotype processes, precursors to photographic processes of the later ...
in his patent for an enlarger for his
calotype process which produced a
paper negative The paper negative process consists of using a negative printed on paper (either photographically or digitally) to create the final print of a photograph, as opposed to using a modern negative on a film base
A film base is a transparent substrat ...
, mentions that using lenses it is possible to produce a large negative from a smaller, so having made such enlargements has a priority claim to be the inventor of a system for making an enlarged print from a negative, though it did not go into production and was not practical given the lengthy exposures required.
In 1848 Talbot recommended to fellow photographer Thomas Malon the enlarging camera made by Thomas Ross of lens manufacturers Ross, Andrew & Thomas.
The advent of
collodion
Collodion is a flammable, syrupy solution of nitrocellulose in ether and alcohol. There are two basic types: flexible and non-flexible. The flexible type is often used as a surgical dressing or to hold dressings in place. When painted on the skin, ...
negatives on glass in the 1850s made enlargement more practical. Achille Quinet's invention of 1852 used artificial light, but was inefficient, requiring very extended exposures. David Acheson Woodward's 1857 'solar enlarging camera' addressed that problem by tapping the brightest light-source then available – the Sun – with mirrors and a condenser.
Solar camera
Solar cameras, introduced in the late 1850s, and ancestors of the darkroom enlarger, were necessary because of the low light sensitivity of albumen and calotype materials used. A larger version of the 18th century
solar microscope, they were first freestanding, a design analogous to picture-taking cameras but with the relative position of negative and lens reversed so that sunlight shone through the glass plate to be projected onto photo-sensitive paper inside the instrument. Mounted on a stand, they could be rotated to continuously face the sun.
Woodward's 1857 solar enlarging camera was a large instrument operated out-of-doors that could produce life size prints from quarter plate and half plate negatives with an exposure of about forty-five minutes, improved in the 1860s and 70s with a clockwork
heliostat
A heliostat (from ''helios'', the Greek word for ''sun'', and ''stat'', as in stationary) is a device that includes a mirror, usually a plane mirror, which turns so as to keep reflecting sunlight toward a predetermined target, compensating ...
to rotate the mirror in synchronisation with the sun's passage to concentrate its light on the condenser lens, while
Désiré van Monckhoven's 1863 patent was for a modification of Woodward's design that had an appearance more like a modern horizontal enlarger.
The instrument was used by significant photographers Disderi and Nadar. By 1890, artificial light sources – gas, petroleum, limelight, magnesium, and electric light bulb – were commonly used in enlargers,
[C. H. Bothamley (ed.) ''Ilford Manual of Photography''. London: Hazell, Watson and Viney, 1891] but even at the turn of the century simple folding daylight enlargers still found a use among amateurs to easily produce prints of a fixed size. Some cameras were made convertible to use in a similar manner.
Commercial enlarging
In the 1870s hand-coloured enlargements from
carte-de-visite
The ''carte de visite'' (, visiting card), abbreviated CdV, was a type of small photograph which was patented in Paris by photographer André Adolphe Eugène Disdéri in 1854, although first used by Louis Dodero. Each photograph was the size of ...
prints and daguerreotypes as well as existing negatives were offered for sale in London for two shillings for an A4 print, and three pounds for a life size bust, and R. L. Elliot & Co., of
King’s Road could print up to 25" x 20" from quarter plate negatives in 1878 using
limelight, as suggested by
John Benjamin Dancer
John Benjamin Dancer (8 October 1812 – 24 November 1887) was a British scientific instrument maker and inventor of microphotography. He also pioneered stereography.
Life
By 1835, he controlled his father's instrument making business in Li ...
.
Fast
bromide
A bromide ion is the negatively charged form (Br−) of the element bromine, a member of the halogens group on the periodic table. Most bromides are colorless. Bromides have many practical roles, being found in anticonvulsants, flame-retardant ...
and chloride printing papers largely superseded
albumen
Egg white is the clear liquid (also called the albumen or the glair/glaire) contained within an egg. In chickens it is formed from the layers of secretions of the anterior section of the hen's oviduct during the passage of the egg. It forms aro ...
emulsions in the 1880s.
[C. H. Bothamley (ed.) ''Ilford Manual of Photography''. London: Hazell, Watson and Viney, 1891]
Types of enlarger
A condenser enlarger consists of a light source, a condensing
lens
A lens is a transmissive optical device which focuses or disperses a light beam by means of refraction. A simple lens consists of a single piece of transparent material, while a compound lens consists of several simple lenses (''elements''), ...
, a holder for the negative and a projecting lens. The condenser provides even illumination to the negative beneath it. Condenser enlargers produce higher
contrast than diffusers because light is scattered from its path by the negative's image silver; this is called the
Callier effect. The condenser's increased contrast emphasises any negative defects, such as dirt and scratches, and image grain.
A point source enlarger is a variation of the condenser enlarger designed to cut light diffusion above the negative. Contrast is enhanced and grain in the resultant print is sharper than with a conventional enlarger, and the transition from light to dark at the edge of the shadow areas is dramatic.
An unfrosted clear lamp with a tiny filament is used without diffusers.
As the illuminant is narrow the lamp must be precisely positioned both vertically and horizontally, because the condensers project only that single small filament rather than light that fills the whole housing. However the lens must be kept at full aperture to avoid projecting an image of the light source restricted to the centre of the baseboard, which will cause vignetting and falloff in the print. Exposure is controlled through duration or using a variable transformer.
A diffuser enlarger's light source is
diffused
Molecular diffusion, often simply called diffusion, is the thermal motion of all (liquid or gas) particles at temperatures above absolute zero. The rate of this movement is a function of temperature, viscosity of the fluid and the size (mass) of ...
by translucent glass or plastic, providing even illumination for the film. Diffuser enlargers produce an image of the same contrast as a contact print from the negative.
Cold light or cold cathode enlargers employ diffusion enlarger heads with a coiled
Fluorescent lamp
A fluorescent lamp, or fluorescent tube, is a low-pressure mercury-vapor gas-discharge lamp that uses fluorescence to produce visible light. An electric current in the gas excites mercury vapor, which produces short-wave ultraviolet lig ...
tube rather than a conventional light bulb.
Their light is blue-rich, in an area of the spectrum to which
silver gelatin paper is sensitive, and therefore exposure is shorter comparative to that with other light sources, ideal for making large mural prints which require extended exposure, and heat is reduced which is beneficial in avoiding buckling or 'popping' of negatives, and also are
Newton's rings
Newton's rings is a phenomenon in which an interference pattern is created by the reflection of light between two surfaces, typically a spherical surface and an adjacent touching flat surface. It is named after Isaac Newton, who investigated the ...
' where a glass negative carrier is used. They produce a softer (less contrasty) print.
Color enlargers typically contain an adjustable filter mechanism - the
color head - between the light source and the negative, enabling the user to adjust the amount of
cyan
Cyan () is the color between green and blue on the visible spectrum of light. It is evoked by light with a predominant wavelength between 490 and 520 nm, between the wavelengths of green and blue.
In the subtractive color system, or CMYK color ...
,
magenta
Magenta () is a color that is variously defined as pinkish- purplish-red, reddish-purplish-pink or mauvish-crimson. On color wheels of the RGB (additive) and CMY (subtractive) color models, it is located exactly midway between red and blue. I ...
and
yellow
Yellow is the color between green and orange on the spectrum of light. It is evoked by light with a dominant wavelength of roughly 575585 nm. It is a primary color in subtractive color systems, used in painting or color printing. In the R ...
light reaching the negative to control
color balance
In photography and image processing, color balance is the global adjustment of the intensities of the colors (typically red, green, and blue primary colors). An important goal of this adjustment is to render specific colors – particularly ne ...
. Other models have a drawer where cut filters can be inserted into the light path, synthesize colour by
additive mixing of light from colored lamps with adjustable intensity or duty cycle, or expose the receiving medium sequentially using red, green and blue light. Such enlargers can also be used with variable-contrast monochrome papers.
Digital enlargers project an image from an LCD screen at the
film plane
A film plane is the surface of an image recording device such as a camera, upon which the lens creates the focused image. In cameras from different manufacturers, the film plane varies in distance from the lens. Thus each lens used has to be chos ...
, to produce a photographic enlargement from a digital file.
Enlarger physical arrangements
Most modern enlargers are vertically mounted with the head pointing downward and adjusted up or down to change the size of the image projected onto the enlarger's base, or a work table if the unit is mounted to the wall.
A horizontal enlarger consists of a trestle, with the head mounted on crossbars between two or more posts for extra stability. A horizontal enlarger structure is used when high quality,
large format
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 o ...
enlargements are required such as when photographs are taken from aircraft for mapping and taxation purposes.
The parts of the enlarger include baseboard, enlarger head, elevation knob, filter holder, negative carrier, glass plate, focus knob, girder scale, timer, bellows, and housing lift.
Principles of operation
The image from the negative or transparency is projected through a lens, typically fitted with an adjustable
aperture
In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane.
An opt ...
, onto a flat surface bearing the sensitized
photographic paper. By adjusting the ratio of distance from film to lens to the distance from lens to paper, various degrees of enlargement may be obtained, with the physical enlargement ratio limited only by the structure of the enlarger and the size of the paper. As the image size is changed it is also necessary to change the focus of the lens. Some enlargers, such as
Leica's "Autofocus" enlargers, perform this automatically.
An
easel
An easel is an upright support used for displaying and/or fixing something resting upon it, at an angle of about 20° to the vertical. In particular, easels are traditionally used by painters to support a painting while they work on it, normally ...
is used to hold the paper perfectly flat. Some easels are designed with adjustable overlapping flat steel "blades" to crop the image on the paper to the desired size while keeping an unexposed white border about the image. Paper is sometimes placed directly on the table or enlarger base, and held down flat with metal strips.
The enlargement is made by first focusing the image with the lamp on, the lens at maximum aperture and the easel empty, usually with the aid of a
focus finder. The lamp is turned off, or in some cases, shuttered by a light-tight mechanism.
The image is focused by changing the distance between the lens and the film, achieved by adjusting the length of a light-tight bellows with a geared
rack and pinion
A rack and pinion is a type of linear actuator that comprises a circular gear (the '' pinion'') engaging a linear gear (the ''rack''). Together, they convert rotational motion into linear motion. Rotating the pinion causes the rack to be driven ...
mechanism.
The lens is set to its working aperture. Enlarging lenses have an optimum range of apertures which yield a sharp image from corner to corner, which is 3 f/ stops smaller than the maximum aperture of the lens. For an enlarging lens with a maximum aperture of f/2.8, the optimal aperture would be f/8. The lens is normally set to this aperture and any color filtration dialed in, if making a color print or one on variable-contrast black-and-white paper.
A series of test strips, and/or a stepped series of exposures made on the one sheet of paper, are undertaken to determine exposure, and then contrast or colour filtration. Alternatively a custom incident
light meter
A light meter is a device used to measure the amount of light. In photography, a light meter (more correctly an exposure meter) is used to determine the proper exposure for a photograph. The meter will include either a digital or analog calcul ...
(
densitometer
A densitometer is a device that measures the degree of darkness (the optical density) of a photographic or semitransparent material or of a reflecting surface. The densitometer is basically a light source aimed at a photoelectric cell. It determ ...
or 'colour-' or 'darkroom analyser') may be used in setting exposure once the degree of enlargement has been decided, and in colour printing may also be used to establish a base neutral filtration from the negative rebate.
The enlarger's lamp or shutter mechanism is controlled either by an electronic timer, or by the operator - who marks time with a clock, metronome or simply by counting seconds - shuttering or turning off the lamp when the exposure is complete. The exposed paper can be processed immediately or placed in a light-tight container for later processing.
Digitally controlled commercial enlargers typically adjust exposure in steps known as
printer points; twelve printer points makes a factor of two change in exposure.
If a greater or lesser enlargement from the same negative is then required, a calculator – analogue, digital or in app format – may be used to quickly extrapolate from the original settings the exposure without the need for labour-intensive re-testing.
Paper processing
After exposure, photographic paper is developed, fixed, washed and dried using the
gelatin silver
The gelatin silver process is the most commonly used chemical process in black-and-white photography, and is the fundamental chemical process for modern analog color photography. As such, films and printing papers available for analog photography ...
or
C-print process.
Automated print machines
Automated photo print machines have the same basic elements and integrate each of the steps outlined above in a single complex machine under operator and
computer
A computer is a machine that can be programmed to Execution (computing), carry out sequences of arithmetic or logical operations (computation) automatically. Modern digital electronic computers can perform generic sets of operations known as C ...
control.
Rather than project directly from the film negative to the print paper, a digital image may first be captured from the negative. This allows the operator or computer to quickly determine adjustments to brightness, contrast, clipping, and other characteristics. The image is then rendered by passing light through the negative and a built-in computer-controlled enlarger optically projects this image to the paper for final exposure.
As a byproduct of the process a
compact disc
The compact disc (CD) is a Digital media, digital optical disc data storage format that was co-developed by Philips and Sony to store and play digital audio recordings. In August 1982, the first compact disc was manufactured. It was then rele ...
recording may be made of the digital images, although a subsequent print made from these may be quite inferior to an image made from the negative due to digitization noise and lack of dynamic range which are characteristics of the digitizing process.
For better images, the negatives may be reprinted using the same automated machine under operator selection of the print to be made.
Advantages
* The image may be printed to a size different from the negative or transparency. Without an enlarger, only a
contact print
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 ...
would be possible, and large images would require large size negatives and hence very large cameras.
* Local contrast and density of various parts of the print can be easily controlled. Changing the amount of light exposing the paper in various areas will change the image density in those areas. A mask with a hole can be used to add extra light to an area
"burning", which will have the effect of darkening the regions with additional exposure, while the use of a small wand to reduce the total exposure to a region is called "
dodging
Dodging and burning are terms used in photography for a technique used during the printing process to manipulate the exposure of select areas on a photographic print, deviating from the rest of the image's exposure. In a darkroom print from a fil ...
" and has the effect of lightening the regions with reduced exposure. The tool is kept moving to avoid producing a sharp edge at the region boundary. Using these techniques it is possible to make significant changes to the mood or emphasis of a photographic print. Similar methods are available with contact printing, but it is more difficult to see the image as it is being manipulated.
*It is also possible to make composite photographs, such as those by
Jerry Uelsmann
Jerry Norman Uelsmann (June 11, 1934 – April 4, 2022) was an American photographer.
As an emerging artist in the 1960s, Jerry Uelsmann received international recognition for surreal, enigmatic photographs (photomontages) made with his uniqu ...
, by overlaying the print with a hand-cut mask, performing an exposure, and then using the inverse of that mask to perform another exposure with a different negative. This is much more difficult to do well using photographic methods than it is now by using the methods of modern
digital image manipulation
Image editing encompasses the processes of altering images, whether they are digital photographs, traditional photo-chemical photographs, or illustrations. Traditional analog image editing is known as photo retouching, using tools such a ...
.
Image enlargement limits
The practical amount of enlargement (irrespective of the enlarger structure) will depend upon the grain size of the negative, the sharpness (accuracy) of both the camera and projector lenses, blur in the image due to subject motion and camera shake during the exposure.
The intended viewing distance for the final product is a consideration. For example, an enlargement from a certain negative as a 12 x 18 cm (approx. 5 by 7 inch) print may be sufficient for a
scrapbook
Scrapbook may refer to:
* Scrapbooking, the process of making a scrapbook
Software
* Scrapbook, an early (1970s) information storage and retrieval system
* Scrapbook (Mac OS), a Mac OS application
* ScrapBook, a Firefox extension
Film and TV ...
viewed at 50 cm (20 inches), but insufficiently detailed for an A4 print hung on a hallway wall to be viewed at the same distance, though usable at a larger 120 x 180 cm (ten times larger) on a
billboard
A billboard (also called a hoarding in the UK and many other parts of the world) is a large outdoor advertising structure (a billing board), typically found in high-traffic areas such as alongside busy roads. Billboards present large advertise ...
to be viewed no closer than 5 metres.
Since the
inverse square law applies to illumination intensity at increasing distance, enlargement beyond a certain size becomes impractical, requiring extended exposure times and dependent on the extent to which dampening of enlarger supports may eliminate vibration causing blur in the resulting print.
Biggest enlargement
The claim for the biggest analogue enlargement ever made from a 35mm photograph is that for
Ernst Haas
Ernst Haas (March 2, 1921 – September 12, 1986) was an Austrian-American photojournalist and color photographer. During his 40-year career, Haas bridged the gap between photojournalism and the use of photography as a medium for expression an ...
' wildlife picture taken in Kenya in 1970. It required a 5-hour exposure using the Kodak
Colorama process, for a giant transparency. The 508-times enlargement consisted of 20 vertical panels of 3 feet width and 18 feet height (91.4 x 548.6 cm) for a total size of 18 x 60 feet (5.48 m x 18.28 m). Displayed at
Grand Central Station
Grand Central Terminal (GCT; also referred to as Grand Central Station or simply as Grand Central) is a commuter rail terminal located at 42nd Street and Park Avenue in Midtown Manhattan, New York City. Grand Central is the southern terminus ...
in New York in 1977, it was Illuminated from behind with 61,000 watts of light; it was the first time a 35 mm picture had been used for an ongoing series of Kodak advertising displays there c.1950–1990. The transparency print was destroyed after exhibition.
Manufacturers
As the photographic market shifts away from film-based towards electronic imaging technology, many manufacturers no longer make enlargers for the professional photographer.
Durst, which made high quality enlargers, stopped producing them in 2005, but still supports already sold models. Manufacturers old and new include:
*
Agfa
*
Beseler
*
Bogen
*
De Vere
*
Durst
*
Dunco
*
enLARGE
*
Fuji Fuji may refer to:
Places China
* Fuji, Xiangcheng City (付集镇), town in Xiangcheng City, Henan
Japan
* Mount Fuji, the tallest mountain in Japan
* Fuji River
* Fuji, Saga, town in Saga Prefecture
* Fuji, Shizuoka, city in Shizuoka Prefec ...
*
Gnome Photographic Products
*
Kaiser Fototechnik
*
Kienzle Phototechnik
*
Kindermann
*
Klatt
*
Leitz Leitz may refer to several German companies:
*Esselte Leitz GmbH & Co KG, founded by Louis Leitz in 1896, a German manufacturer of office products
**Louis Leitz (1846–1918), German inventor and founder of Esselte Leitz GmbH & Co KG
* Leitz GmbH & ...
*
Liesegang
Liesegang rings () are a phenomenon seen in many, if not most, chemical systems undergoing a precipitation reaction under certain conditions of concentration and in the absence of convection. Rings are formed when weakly soluble salts are produc ...
*
Linhof
Linhof is a German company, founded in Munich in 1887 by Valentin Linhof. The company is well known for making premium rollfilm and large format film cameras. Linhof initially focused on making camera shutters and developing the first leaf shu ...
*
LPL
* Lucky (now owned by Kenko)
*
Meopta
Meopta - optika, s.r.o. is a Czech Republic based company that manufactures various products mainly in the field of optics. The company was once well-known for its still and movie cameras, although it no longer manufactures such products.
Histo ...
*
Omega
Omega (; capital: Ω, lowercase: ω; Ancient Greek ὦ, later ὦ μέγα, Modern Greek ωμέγα) is the twenty-fourth and final letter in the Greek alphabet. In the Greek numeric system/isopsephy (gematria), it has a value of 800. The wo ...
* Ōmiya Shashin-yōhin K.K.
*
Paul Teufel & Cie Photogerätebau
Paul may refer to:
*Paul (given name), a given name (includes a list of people with that name)
*Paul (surname), a list of people
People
Christianity
* Paul the Apostle (AD c.5–c.64/65), also known as Saul of Tarsus or Saint Paul, early Chri ...
*
Polskie Zakłady Optyczne
*
Sun Ray Photo Company
See also
*
Contact print
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 si ...
er for a non-enlarging method of producing photographic prints;
*
Gelatin silver process
The gelatin silver process is the most commonly used chemical process in black-and-white photography, and is the fundamental chemical process for modern analog color photography. As such, films and printing papers available for analog photography ...
for an overview of the dominant photographic printmaking process;
*
Image projector
A projector or image projector is an optical device that projects an image (or moving images) onto a surface, commonly a projection screen. Most projectors create an image by shining a light through a small transparent lens, but some newer typ ...
for a directory of projector types;
*
Overhead projector
An overhead projector (often abbreviated to OHP), like a film or slide projector, uses light to project an enlarged image on a screen, allowing the view of a small document or picture to be shared with a large audience.
In the overhead project ...
for another use of a similar design, for display;
*
Epidiascope for a design that could project images of opaque originals;
*
Photographic printing
Photographic printing is the process of producing a final image on paper for viewing, using photographic paper, chemically sensitized paper. The paper is exposed to a photographic Negative (photography), negative, a positive reversal film, transpa ...
for an overview of analogue photographic printmaking methods.
Notes
References
{{Photography
Photography equipment