Motion blur

Motion blur is the apparent streaking of rapidly moving objects in a still image or a sequence of images such as a movie or animation.

When a camera creates an image, that image does not represent a single instant of time. Because of technological constraints or artistic requirements, the image represents the scene over a period of time. As objects in a scene move, an image of that scene must represent an integration of all positions of those objects, as well as the camera's viewpoint, over the period of exposure determined by the shutter speed. In such an image, any object moving with respect to the camera will look blurred or smeared along the direction of relative motion. This smearing may occur on an object that is moving or on a static background if the camera is moving. In a film or television image, this looks natural because the human eye behaves in much the same way.

Because the effect is caused by the relative motion between the camera, and the objects and scene, motion blur may be avoided by panning the camera to track those moving objects. In this case, even with long exposure times, the objects will appear sharper, and the background more blurred.

Light painting

Light painting, also known as light drawing is a photographic technique in which exposures are made usually at night or in a darkened room by moving a light source or by moving the camera.

The light can either be used to selectively illuminate parts of the subject or to "paint" a picture by shining it directly into the camera lens. Light painting requires a sufficiently slow shutter speed, usually a second or more. Like night photography, it has grown in popularity since the advent of digital cameras because it allows photographers to see the results of their work immediately.

Light painting can take on the characteristics of Tableaux Vivant or a quick pencil sketch. Pablo Picasso was photographed in 1924 doing a quick sketch in the air.

Lead room

In photography, filmography and other visual arts, lead room, or sometimes nose room, is the space in front, and in the direction, of moving or stationary subjects. Well-composed shots leave space in the direction the subject is moving. When the human eye scans a photograph for the first time it will expect to see a bit on front of the subject.

For example, moving objects such as cars require lead room. If extra space is allowed in front of a moving car, the viewer can see that it has someplace to go; without this visual padding, the car's forward progress will seem impeded.

Kite aerial photography

Kite aerial photography (KAP) is a hobby and a type of photography. A small camera is suspended from a kite on a Picavet and is used to take aerial photographs. The camera rigs can range from the extremely simple, consisting of a trigger mechanism with a disposable camera, to complex apparatuses using radio control and digital cameras. On some occasions it can be a good alternative (in many ways) to any other form of aerial photography.

The example image of San Francisco after the 1906 San Francisco earthquake was taken by an early pioneer in KAP, George Lawrence using a large panoramic camera and stabilizing rig he designed.

The first kite aerial photograph was taken by Arthur Batut in Labruguière (France) in 1888.

Infrared photography

In infrared photography, the film or image sensor used is sensitive to infrared light. The part of the spectrum used is referred to as near-infrared to distinguish it from far-infrared, which is the domain of thermal imaging. Wavelengths used for photography range from about 700 nm to about 900 nm. Usually an "infrared filter" is used; this lets infrared (IR) light pass through to the camera but blocks all or most of the visible light spectrum (and thus looks black or deep red).

When these filters are used together with infrared-sensitive film or sensors, very interesting "in-camera effects" can be obtained; false-color or black-and-white images with a dreamlike or sometimes lurid appearance known as the "Wood Effect."

The effect is mainly caused by foliage (such as tree leaves and grass) strongly reflecting in the same way visible light is reflected from snow. Chlorophyll is transparent at these wavelengths and so does not block this reflectance (see Red edge). There is a small contribution from chlorophyll fluorescence, but this is extremely small and is not the real cause of the brightness seen in infrared photographs.

The other attributes of infrared photographs include very dark skies and penetration of atmospheric haze, caused by reduced Rayleigh scattering and Mie scattering (respectively) in the atmosphere compared to visible light. The dark skies, in turn, result in less infrared light in shadows and dark reflections of those skies from water, and clouds will stand out strongly. These wavelengths also penetrate a few millimeters into skin and give a milky look to portraits, although eyes often look black.

Harris Shutter

The Harris Shutter is a bit of a misnomer, being a technique, rather than a piece of photographic equipment.

The effect is produced by re-exposing the same frame of film through Red, Green and Blue filters in turn, whilst keeping the camera steady. This will generate a rainbow of colour around any object that moves within the frame. Some good candidates for subjects include waterfalls (pictured, right), clouds blowing over a landscape or people walking across a busy town square.

Traditionally, the technique is either achieved using a camera that allows in-register multiple exposures, and changing filters on the front of the lens. Another alternative was to make a drop through filter that consisted of the three coloured gels and two opaque sections that is literally dropped through a filter holder during exposure.

With the advent of digital photography, the process has become a lot simpler - the photographer can simply take three colour photographs on location, and then use software to take the Red channel from one exposure, combine with the blue and green channels from the other two photos to good effect - this even allows for correction of movement if the camera is inadvertently moved between exposures.

Photographic processing

Conventional photographic films and papers need to be chemically processed after they have been exposed in order to produce the desired negative or positive image. The general process is similar whatever the make of film or paper. The only obvious exceptions are a few proprietary makes such as Polaroid and other instant self-processing techniques; Kodachrome which cannot be processed except in Kodak laboratories. There are also a small number of relatively uncommon processes using dye decomposition technologies such as Cibachrome.

Development does three things: it transforms the latent image into a visible image that can be seen, it makes the visible image permanent and resistant to deterioration with time, and it renders the film insensitive to light.

Digiscoping

Digiscoping is a method of obtaining photos using a digital camera through a telescope or, less often, binoculars. Afocal projection is a method of astrophotography in which photographs are taken by holding or mounting the camera over the telescope eyepiece, with the camera taking the place of your eye. Afocal projection is the method most commonly associated with digiscoping.

Cyanotype

Cyanotype is an old monochrome photographic printing process that gives a cyan-blue print.

The English scientist and astronomer Sir John Herschel discovered this procedure in 1842. Though Herschel is perhaps the inventor of the cyanotype process, it was Anna Atkins, a British scientist, who brought the process into the realm of photography. She created a limited series of cyanotype books that documented ferns and other plant life. By using this process, Anna Atkins is regarded as the first woman photographer.

The process uses two chemicals:

* Ammonium iron(III) citrate
* Potassium ferricyanide

They result in a photo-sensitive solution when dissolved in water, which is used to coat a material (usually paper). A positive image can be produced by exposing it to a source of ultraviolet light (such as sunlight) with a negative. The UV light reduces the iron(III) to iron(II). This is followed by a complex reaction of the iron(II) complex with ferricyanide. The result is an insoluble, blue dye (ferric ferrocyanide) known as Prussian blue.

The developing of the picture takes place by flushing it with flowing water. The water-soluble iron(III) salts are washed away, while the non-water-soluble Prussian blue remains in the paper. This is what gives the picture its typical blue color. The process was popular in engineering circles well into the 20th century. The simple and low-cost process enabled them to produce large-scale copies of their work, referred to as blueprints.

Cross processing

Cross processing (sometimes abbreviated to xpro) is the procedure of deliberately processing photographic film in a chemical solution intended for a different type of film.

Cross processing usually involves one of the two following methods:

* Processing positive color reversal film in C-41 chemicals, resulting in a negative image on a colorless base
* Processing negative color print film in E-6 chemicals, resulting in a positive image but with the orange base of a normally processed color negative.

Astrophotography

Astrophotography ranges from simple images of bright objects to very complex exposures designed to reveal objects that are too faint to observe with the naked eye. With only a few exceptions, almost all astrophotography employs time exposures since both film and digital cameras can accumulate and sum light photons over long periods of time. This is just one of many distinct aspects of astrophotography that sets it apart from conventional photography.

Astrophotography poses challenges that are distinct from normal photography, because most subjects are usually quite faint, and are often small in angular size. Effective astrophotography requires the use of many of the following techniques:

* Mounting the camera at the focal point of a large telescope
* Film emulsions with low light sensitivity or specialized CCD cameras
* Very long exposure times and/or multiple exposures (often more than 20 per image).
* Accurate tracking of the subject to compensate for the rotation of the Earth during the exposure
* Use of filters to reduce background fogging due to light pollution of the night sky.

Aerial photography

Aerial photography is the taking of photographs of the ground while not supported by a ground-based structure. Cameras may be hand held or mounted, and photographs may be taken by an active photographer, or triggered remotely or automatically. Vehicles for aerial photography include fixed-wing aircraft and helicopters; balloons, blimps and dirigibles; and rockets. kites can also be made into platforms, as can skydivers.

Aerial photography was first practiced by the French photographer and balloonist Nadar in 1858 over Paris, France. The use of aerial photography for military purposes was expanded during World War I by aviators such as Fred Zinn.

Aerial photography is used in cartography (particularly in photogrammetric surveys, which are often the basis for topographic maps), land-use planning, archeology, movie production, environmental studies, espionage, commercial advertising, conveyancing, and other fields. In the United States, aerial photographs are analyzed in preparation of many Phase I Environmental Site Assessments for real property analysis. Aerial photos are often processed by a GIS system.

Advances in radio controlled models has made it possible for radio controlled model aircraft to conduct low-altitude aerial photography. This has benefited real-estate advertising, where commercial and residential properties are the photographic subject. Full-size, manned aircraft are prohibited from low flyovers of populated locations. Miniature-size model aircraft offer full photographic access to these previously restricted areas. Miniature vehicles do not replace full-size aircraft, as full-size aircraft are capable of longer flight-times, higher altitudes, and greater equipment payloads.

Because anything capable of being viewed from a public space is considered outside the realm of privacy in the United States, aerial photography may legally document features and occurrences on private property.

For amateurs without a pilot license aerial photographs can be made using an Astrocam or an Oracle model rocket.

Wildlife photography

Wildlife photography is the act of taking photographs of wildlife. The art of good wildlife photography is regarded as being one of the more challenging forms of photography as it has several different requirements.

* Being a technically sound photographer, thus being able to expose correctly to have the desired effect of a wildlife photograph.
* Advanced photographic equipment. While wildlife photographs can be taken effectively using basic equipment it is facilitated by being able to use more sophisticated equipment. For example, 600mm lenses in conjunction with the latest autofocus camera bodies are generally required for bird photography. However different equipment is needed depending on the situation.
* Good field craft skills. Wildlife in general is difficult to approach thus a knowledge of the animal's behaviour will be needed in order to be able to predict actions. An ability to stalk animals effectively is often also required when attempting to get closer to wildlife. Hides are often required when photographing more timid subjects as these effectively conceal the photographer, although they prevent the photographer from moving in order to re-position a photograph.

VR photography

VR photography is the name the emerging field of virtual reality photography is being called.

VR photography is the art of capturing or creating a complete scene as a single image, as viewed when rotating about a single central position. Normally created by stitching together a number of photographs taken in a multi-row 360 degree rotation; the complete image can also be a totally computer generated effect, or a composite of real word photography and computer generated objects.

The composite image created is known as a VR Panorama and is a fully interactive digital image where "the viewer" is placed in the centre of a cylinder or a sphere onto which is projected a 360 degree wrap-around image; within which the viewer can rotate horizontally and vertically, as if they were immersed within the real world scene.

VR Panoramas are viewed through movie players such as Apple's QuickTime VR software which may be installed as part of a Web browser plug-in, or as a stand-alone player on a computers desktop or CD Rom. Whilst QuickTimeVR (QTVR) was the original player program there are now a growing number of different players and plug-ins, each with their own features, all helping to make VR Photography more popular than ever.

As of early 2007 the term "VR Photography" is still a fairly new one, but describes a process that has its foundation in the photography used in Virtual Tours since around 1995. However the ever increasing data speeds of internet connections now allow a much larger images to be published online, as such these larger file sizes allow VR Photographers to create higher resolution full-screen images with much more detail that helps to immerse the viewer into the scene.

Vernacular photography

Vernacular photography refers to the creation of photographs by amateur or unknown photographers who take everyday life and common things as subjects. Examples of vernacular photographs include travel and vacation photos, family snapshots, photos of friends, class portraits, identification photographs, and photobooth images. Vernacular photographs can also be considered types of "accidental" art, in that they often are unintentionally artistic in some way.

Closely related to vernacular photography is "found photography," which in one sense refers to the recovery of a "lost," unclaimed, or discarded vernacular photograph or snapshot. Found photos can be "found" at flea markets, thrift stores, yard sales, estate sales, in dumpsters and trash cans, between the pages of books, or on sidewalks.

Also, the use of vernacular photography in the arts is almost as old as photography itself. Vernacular photography has become far more commonplace in recent years as an art technique and is now a widely accepted genre of art photography. Artists who have made extensive use of vernacular photography in their work include Stephen Bull, Dick Jewell, Patrick McCoy, and Joachim Schmid.

Travel photography

Travel photography is a subcategory of photography that is characterized by documenting the landscapes, inhabitants, cultures, customs and history of a specific region of the world.

From the Photographic Society of America (PSA):

What is a Photo Travel Image?
It's an image that expresses the feeling of a time and place, portrays a land, its people, or a culture in its natural state, and has no geographical limitations.

Travel photography can be commercial in nature, done by professional photographers. The most well-known example is the pictures seen in the National Geographic magazine.

There is also amateur travel photography, represented by the kind of pictures taken by most tourists.

Street photography

Street photography uses the techniques of straight photography in that it shows a pure vision of something, like holding up a mirror to society. This genre of photography is present in contemporary times and is usually done as black and white photographs. Street photography tends to be ironic and distanced from its subject matter and often concentrates on a single human moment, caught at a decisive or poignant moment. In the 20th century, street photographers have provided an exemplary and detailed record of street culture in Europe and North America.

Many classic works of street photography were created in the period between roughly 1890 and 1975 and coincided with the introduction of small 35mm, rangefinder cameras. Classic practitioners of street photography include Henri Cartier-Bresson, Robert Frank, Alfred Eisenstaedt, W. Eugene Smith, William Eggleston, Brassaї, Willy Ronis, Robert Doisneau and Garry Winogrand.

Stock photography

Stock photography consists of existing photographs that can be licensed for specific uses. Book publishers, specialty publishers, magazines, advertising agencies, filmmakers, web designers, graphic artists, interior decor firms, corporate creative groups, and others use stock photography to fulfill the needs of their creative assignments.

A customer who uses stock photography instead of hiring a photographer can save time and money, but can also sacrifice creative control. Stock images can be presented in searchable online databases, purchased online, and delivered via download or email.

A collection of stock photography may also be called a photo archive, picture library, image bank or photo bank. As modern stock photography distributors often carry stills, video, and illustrations, none of the existing terminology provides a perfect match.

Still life photography

Still life photography is the practice or products of depicting inanimate subject matter, typically commonplace objects which may be either natural or man-made. Still life is the photography of small groups of objects, either found or put together for the purpose. Still life photography gives the photographer more leeway in the arrangement of design elements within a composition than do photographs of other types of subjects such as landscape or portraiture.

Still life photography represents one of the most demanding aspects of photography. In this area the photographer is expected to have a highly refined sense of lighting coupled with superb compositional skills because the photographer is making pictures rather than taking them. Knowing where to look for propping and surfaces is also a valuable trait.

In addition to knowing the fundamentals of photography, successful still life photographers are intimately familiar with the tools of this field: tremendous studio lighting skills, ability to use large format view cameras, a strong visual technique, and distinctive stylistic approach.

Still life is one of the hardest of photographic genres to define. Portraits, nudes, architecture, lingerie, even special effects all raise certain expectations; but still life is another matter. It ranges from advertising shots to the most personal of work; from pictures that can take days to assemble in the studio, to those that are "found" compositions and are photographed by available light in a few moments; from subjects no bigger than the palm of your hand to those which fill a room.

Sports photography

The equipment used by a professional photographer usually includes a fast telephoto lens and a camera that has an extremely fast shutter speed that can rapidly take pictures.

Sport photography requires long lenses. In general, 200-600mm lenses are used for the reach. In professional sport photography work, Digital single-lens reflex cameras must be used, in order to achieve high rate of successive shots. That means using cameras with ability to take a minimum of 5 frames per second. In general, monopods are used as well, in order to support the camera and the heavy lenses. This minimizes the shaking of the camera.

Portrait photography

The goal of portrait photography is to capture the likeness of a person or a small group of people, typically in a flattering manner. Like other types of portraiture, the focus of photograph is the person's face, although the entire body and the background may be included. Many people enjoy having professionally made family portraits to hang in their homes, or special portraits to commemorate certain events, such as graduations or weddings.

Portrait photography has been around since the invention and popularization of the camera, and is a cheaper and often more accessible method than portrait painting, which had been used by distinguished figures before the use of the camera. The popularity of the daguerreotype in the middle of the 19th century was due in large part to the demand for inexpensive portraiture. Studios sprang up in cities around the world, some cranking out more than 500 plates a day. The style of these early works reflected the technical challenges associated with 30-second exposure times and the painterly aesthetic of the time. Subjects were generally seated against plain backgrounds and lit with the soft light of an overhead window and whatever else could be reflected with mirrors. As the equipment became more advanced, the ability to capture images with short exposure times gave photographer more creative freedom and thus created new styles of portrait photography. Contemporary portrait photographers strive not only to capture a person's likeness, but also the person's mood and thoughts in an instant in time.

As photographic techniques developed, an intrepid group of photographers took their talents out of the studio and onto battlefields, across oceans and into remote wilderness. William Shew's Daguerreotype Saloon, Roger Fenton's Photographic Van and Mathew Brady's What-is-it? wagon set the standards for making portraits and other photographs in the field.

Contemporary artists Cindy Sherman, Barbara Kruger, Mitch Kern and others use portrait photography as a vehicle for cultural criticism.

Photojournalism

Photojournalism is a particular form of journalism (the collecting, editing, and presenting of news material for publication or broadcast) that creates images in order to tell a news story. It is now usually understood to refer only to still images, and in some cases to video used in broadcast journalism. Photojournalism is distinguished from other close branches of photography (such as documentary photography, street photography or celebrity photography) by the qualities of:

* Timeliness - the images have meaning in the context of a published chronological record of events.

* Objectivity - the situation implied by the images is a fair and accurate representation of the events they depict.

* Narrative - the images combine with other news elements, to inform and give insight to the viewer or reader.

Photojournalists must make decisions instantly and carry photographic equipment, often while exposed to the same risks (war, rioting, etc.) that are faced by text-only journalists. The fact that they rarely have the option to stand back or wait until the dangerous parts of an event are over means they may take even more risks.

Photojournalism as a descriptive term often implies the use of a certain bluntness of style or approach to image-making. The photojournalist approach to candid photography is becoming popular as a unique style of commercial photography. For example, many weddings today are shot in photojournalism style resulting in candid images that chronicle the events of the wedding day.

Nature photography

Nature photography refers to a wide range of photography taken outdoors and devoted to displaying natural elements such as landscapes, wildlife, plants, and close-ups of natural scenes and textures. Nature photography tends to put a stronger emphasis on the aesthetic value of the photo than other photography genres, such as photojournalism and documentary photography.

Nature photographs are published in scientific, travel and cultural magazines such as National Geographic Magazine and Audubon Magazine or other more specific magazines such as Outdoor Photographer and Nature's Best Photography, as well as a growing hobby as photography is getting more popular in general.

Miksang

Miksang is a Tibetan word meaning "Good Eye" and represents a form of contemplative photography based on the Dharma Art teachings of Chögyam Trungpa, in which the eye is in synchronisation with the contemplative mind. The result of this particular perception of the world, combined with photography, produces a peculiar and open way of seeing the world. Miksang pictures tend to bring the observer back into the original contemplation state of the author of the picture. The pictures can bring one back to a purer perception of reality that is often neglected. Miksang involves nothing fancy, no special setup; only a visual capture, in the proper state of mind, of everyday's reality.

Macro photography

Macro photography refers to close-up photography; the classical definition that the image projected on the "film plane" (i.e film or a digital sensor) is close to the same size as the subject. On 35 mm film (for example), the lens is typically optimized to focus sharply on a small area approaching the size of the film frame. Most 35mm format macro lenses achieve at least 1:2, that is to say, the image on the film is 1/2 the size of the object being photographed. Many 35mm macro lenses are 1:1, meaning the image on the film is the same size as the object being photographed. Another important distinction is that lenses designed for macro are usually at their sharpest at macro focus distances and are not quite as sharp at other focus distances.

In recent years, the term macro has been used in marketing material to mean being able to focus on a subject close enough so that when a regular 4×6 inch (102×152 mm) print is made, the image is life-size or larger. This requires a magnification ratio of only approximately 1:4, more easily attainable by lens makers.

Landscape art

Landscape art depicts scenery such as mountains, valleys, trees, rivers, and forests. Sky is almost always included in the view, and weather usually is an element of the composition. In the first century A.D., Roman frescoes of landscapes decorated rooms that have been preserved at Pompeii and Herculaneum. Traditionally, landscape art depicts the surface of the earth, but there are other sorts of landscapes, such as moonscapes, for example.

The word landscape is from the Dutch, landschap meaning a sheaf, a patch of cultivated ground. The word entered the English vocabulary of the connoisseur in the late 17th century.

Early in the fifteenth century, landscape painting was established as a genre in Europe, as a setting for human activity, often expressed in a religious subject, such as the themes of the Rest on the Flight into Egypt, the Journey of the Magi, or Saint Jerome in the Desert.

The Chinese tradition of "pure" landscape, in which the minute human figure simply gives scale and invites the viewer to participate in the experience, was well established by the time the oldest surviving ink paintings were executed.

In Europe, as John Ruskin realized, and Sir Kenneth Clark brought to view, landscape painting was the "chief artistic creation of the nineteenth century", with the result that in the following period people were "apt to assume that the appreciation of natural beauty and the painting of landscape is a normal and enduring part of our spiritual activity" In Clark's analysis, underlying European ways to convert the complexity of landscape to an idea were four fundamental approaches: by the acceptance of descriptive symbols, by curiosity about the facts of nature, by the creation of fantasy to allay deep-rooted fears of nature and by the belief in a Golden Age of harmony and order, which might be retrieved.

As explorers, naturalists, mariners, merchants and settlers arrived on the shores of Atlantic Canada in the early centuries of its exploration, they were confronted by what they saw as a hostile and dangerous environment and an unforgiving sea. These Europeans tried to cope with the daunting new land by mapping, recording and claiming it as their own. Their understanding of the specific nature of this land and its inhabitants varied greatly, with observations ranging from highly accurate and scientific to outlandish or fantastic. These observations are documented in the landscape artworks they produced. The best examples of Canadian landscape art can be found in the works of the Group of Seven.

Glamour photography

Glamour photography is the photographing of a model with the emphasis on the subject. Photographers use a combination of cosmetics, lighting and airbrushing techniques to produce the most physically appealing image of the model possible.

Food photography

The art and science of food photography is a specialisation in general commercial photography. Food and Drink Photography is one of the most challenging aspects of still life work.

The main areas of food photography are: Editorial for Magazine and Books on food including but not limited to cook books, advertising and packaging design.

The near perfection, the subtlety of flavour and the almost palatable sense prevalent in some of the best food photography today, is almost never the result of the photographer alone. The food stylist, home economist and props stylist all play very important roles in building a strong image and making an impression.

Forensic photography

Forensic photography (sometimes referred to as forensic imaging or crime scene photography) is the art of producing an accurate reproduction of a crime scene or an accident scene for the benefit of a court. It is part of the process of evidence collecting. It provides investigators with photos of bodies, places, items involved in the crime. Pictures of accidents show broken machinery, or a car crash, and so on. Photography of this kind involves choosing correct lighting, accurate angling of lenses, and a collection of different viewpoints. Scales are often used in the picture so that dimensions of items are recorded on the image.

Fine art photography

Fine art photography, sometimes simply called art photography, refers to high-quality archival photographic prints of pictures that are created to fulfill the creative vision of an individual professional. Such prints are reproduced, usually in limited editions, in order to be sold to dealers, collectors or curators, rather than mass reproduced in advertising or magazines. Prints will sometimes, but not always, be exhibited in an art gallery.

Fashion photography

Fashion photography is a genre of photography devoted to displaying clothing and other fashion items. Fashion photography is most often conducted for advertisements or fashion magazines such as Vogue, Vanity Fair, or Allure. Over time, fashion photography has developed its own aesthetic in which the clothes and fashions are enhanced by exotic locations and story lines.

Erotic photography

Nude pictures prior to 1835 generally consisted of paintings and drawings. That year, Louis-Jacques-Mandé Daguerre invented the first practical process of photography. Unlike earlier photographs, his daguerreotypes had stunning quality and did not fade with time. The new technology did not go unnoticed by artists eager for new ways to depict the undraped feminine form. In Nude photography, 1840–1920, Peter Marshall notes: "In the prevailing moral climate at the time of the invention of photography, the only officially sanctioned photography of the body was for the production of artist's studies. Many of the surviving examples of daguerreotypes are clearly not in this genre but have a sensuality that clearly implies they were designed as erotic or pornographic images".

The daguerreotypes were not without drawbacks, however. The main difficulty was that they could only be reproduced by photographing the original picture. In addition, the earliest daguerreotypes had exposure times ranging from three to fifteen minutes, making them somewhat impractical for portraiture. Since one picture could cost a week's salary, the audience for nudes mostly consisted of artists and the upper echelon of society. Nude stereoscopy began in 1838 and became extremely popular. In 1841, William Fox Talbot patented the calotype process, the first negative-positive process, making possible multiple copies. The technology was immediately employed to reproduce nude portraits.

Documentary photography

Documentary photography usually refers to a type of professional photojournalism, but it may also be an amateur or student pursuit. The photographer attempts to produce truthful, objective, and usually candid photography of a particular subject, most often pictures of people. The pictures usually depict a certain perspective of the photographer.

Usually such photographs are meant for publication, but are sometimes only for exhibition in an art gallery or other public forum. Sometimes an organization or company will commission documentary photography of its activities, but the pictures will only be for its private archives.

Cloudscape photography

Cloudscape photography is photography showing a view of clouds or sky. Photographers such as Robert Davies and Ralph Steiner are noted for producing such images.

Alfred Stieglitz also created a series of photographs of clouds, called "equivalents" (1925-1931). According to an essay on the series at the Phillips Collection website (see external links), "A symbolist aesthetic underlies these images, which became increasingly abstract equivalents of his own experiences, thoughts, and emotions."

Candid photography

The photographic setup of candid photography is best described as un-posed and unplanned, immediate and unobtrusive. This is in contrast to classic photography, which includes aspects such as carefully staged portrait photography, landscape photography or object photography. Candid photography is supposed to catch rare instances of life from the very immersion into it, rather than to produce imagery of still life, to catch rare moments of "reality" which presupposes a definition of "reality."

Candid photography is also set off against the voyeuristic stalking involved in animal photography, sports photography or photographic journalistic intrusion, which all have a very strong technical focus on getting distant objects photographed, e.g. by using telephoto lenses. Candid photography's setup includes a photographer who is typically there with the "subjects" to be photographed if not close, and not hidden. People photographed on candid shots either ignore or accept the close presence of the photographer's camera without posing for photos.

The events documented are often private, they involve people in close relation to something they do, or they involve people's relation to each other. Candids are the kinds of pictures taken at children's birthday parties and on Christmas morning, opening the presents; the pictures a wedding photographer takes at the reception, of people dancing, eating, and socializing with other guests. They are taken at leisure, or at special occasions, they show people as they are when they do not prepare to be photographed.

Architectural photography

Based on the concept of capturing architecture in its most perfect form for posterity, architectural photography is marriage of photographic skill, technical aptitude, artistic vision and whimsical thinking. Often using multiple exposures of the same image, architectural photography blends the "best of the best" to create a visual oasis and an architectural utopia for the structurally excitable. Architectural photography at its best will convey the experience of being in and around a built environment. Some rules to follow when capturing architecture on film are:

* Give Old Buildings Some Space
* Step Back and Use a Telephoto Lens
* Include the Fence
* Shoot Head On Until Morning
* Watch for Shadows
* Watch the Weather
* Showcase the Stairs
* Lead the Viewer
* Create a Natural Frame
* Sculpture is Architecture
* So Are Swimming Pools and Fountains
* Don't Be Afraid To Light Up
* Shoot During "Blue Hour"

Since the advent of the DSLR camera much has been said and written about Architectural Photography and its ability to make a healthier space than what truly exists. A good example of this argument is found here and written by photographer Mark Citret.

Angle of view

In photography, angle of view describes the angular extent of a given scene that is imaged by a camera. It parallels, and may be used interchangeably with, the more general visual term field of view.

The angle of view of a camera is a function of three parameters:

1. The dimensions of the film format or image sensor;
2. The focal length of the photographic lens projecting the image; and
3. The kind and degree of distortion of the lens.

It follows that for lenses projecting rectilinear (non-spatially-distorted) images, the film format or image sensor dimensions completely define the angle of view for any given lens focal length.

Angle of view is usually measured one of three ways:

* horizontally (from the left to right edge of the frame)
* vertically (from the top to bottom of the frame)
* diagonally (from one corner of the frame to its opposite corner)

Aperture

In optics, an aperture is a hole or an opening through which light is admitted. More specifically, the aperture of an optical system is the opening that determines the cone angle of a bundle of rays that come to a focus in the image plane.

An optical system typically has many openings, or structures that limit the ray bundles (ray bundles are also known as pencils of light). These structures may be the edge of a lens or mirror, or a ring or other fixture that holds an optical element in place, or may be a special element such as a diaphragm placed in the optical path to limit the light admitted by the system. In general, these structures are called stops, and the aperture stop is the stop that determines the ray cone angle, or equivalently the brightness, at an image point.

In some contexts, especially in photography and astronomy, aperture refers to the diameter of the aperture stop rather than the physical stop or the opening itself. For example, in a telescope the aperture stop is typically the edges of the objective lens or mirror (or of the mount that holds it). One then speaks of a telescope as having, for example, a 100 centimeter aperture. Note that the aperture stop is not necessarily the smallest stop in the system. Magnification and demagnification by lenses and other elements can cause a relatively large stop to be the aperture stop for the system.

Sometimes stops and diaphragms are called apertures, even when they are not the aperture stop of the system.

The word aperture is also used in other contexts to indicate a system which blocks off light outside a certain region. In astronomy for example, a photometric aperture around a star usually corresponds to a circular window around the image of a star within which the light intensity is summed.

Color temperature

Color temperature is a characteristic of visible light that has important applications in photography, videography, publishing and other fields. The color temperature of a light source is determined by comparing its chromaticity with a theoretical, heated black-body radiator. The temperature (in kelvins) at which the heated black-body radiator matches the color of the light source is that source's color temperature; for a black body source, it is directly related to Planck's law.

Depth of field

Precise focus is possible at only one distance; at that distance, a point object will produce a point image. At any other distance, a point object is defocused, and will produce a blur spot shaped like the aperture, which for the purpose of analysis is usually assumed to be circular. When this circular spot is sufficiently small, it is indistinguishable from a point, and appears to be in focus; it is rendered as “acceptably sharp”. The diameter of the circle increases with distance from the point of focus; the largest circle that is indistinguishable from a point is known as the acceptable circle of confusion, or informally, simply as the circle of confusion. The acceptable circle of confusion is influenced by visual acuity, viewing conditions, and the amount by which the image is enlarged. The increase of the circle diameter with defocus is gradual, so the limits of depth of field are not hard boundaries between sharp and unsharp.

Depth of focus

Depth of focus is a lens optics concept that measures the tolerance of placement of the image plane (the film plane in a camera) in relation to the lens. While the phrase depth of focus was historically used, and is sometimes still used, to mean depth of field, in modern times it is more often reserved for the image-side depth. Depth of field is a measurement of depth of acceptable sharpness in the object space, or subject space. Depth of focus, however, is a measurement of how much distance exists behind the lens wherein the film plane will remain sharply in focus. It can be viewed as the flip side of depth of field, occurring on the opposite side of the lens. Where depth of field often can be measured in macroscopic units such as meters and feet, depth of focus is typically measured in microscopic units such as fractions of a millimeter or thousandths of an inch. Since the measurement indicates the tolerance of the film's displacement within the camera, depth of focus is sometimes referred to as "lens-to-film tolerance."

The same factors that determine depth of field also determine depth of focus, but these factors can have different effects than they have in depth of field. Both depth of field and depth of focus increase with smaller apertures. For distant subjects (beyond macro range), depth of focus is relatively insensitive to focal length and subject distance, for a fixed f-number. In the macro region, depth of focus increases with longer focal length or closer subject distance, while depth of field decreases.

In small-format cameras, the smaller circle of confusion limit yields a proportionately smaller depth of focus. In motion picture cameras, different lens mount and camera gate combinations have exact flange focal depth measurements to which lenses are calibrated.

The choice to place gels or other filters behind the lens becomes a much more critical decision when dealing with smaller formats. Placement of items behind the lens will alter the optics pathway, shifting the focal plane. Therefore, often this insertion must be done in concert with stopping down the lens in order to compensate enough to make any shift negligible given a greater depth of focus. It is often advised in 35 mm motion picture filming not to use filters behind the lens if the lens is wider than 25 mm.

A rough formula often used to quickly calculate depth of focus is the product of the focal length times the f-stop divided by 1000; the formula makes most sense in the case of normal lens (as opposed to wide-angle or telephoto), where the focal length is a representation of the format size. The precise formula for depth of focus is two times the f-number times the circle of confusion times the quantity of one plus the magnification factor. However, the magnification factor depends on the focal length and format size and exact focus the lens is set to, which can be difficult to calculate. Therefore, the first formula is often used as a guideline, as it is much easier to calculate. It relies on the historical convention of circle of confusion limit equal to focal length divided by 1000, which is deprecated in modern photographic teachings, in favor of format size (for example, along the diagonal) divided by 1000 or 1500. See the article circle of confusion.

Multiple exposure

Ordinarily cameras have a sensitivity to light that is a function of time. For example, a one second exposure is an exposure in which the camera image is equally responsive to light over the exposure time of one second. The criterion for determining that something is a double exposure is that the sensitivity goes up and then back down. The simplest example of a multiple exposure is a double exposure without flash, i.e. the camera image is responsive to light twice during the complete exposure.

Some single exposures, such as "flash and blur" use a combination of electronic flash and ambient exposure. This effect can be approximated by a Dirac delta measure (flash) and a constant finite rectangular window, in combination. For example, a sensitivity window comprising a Dirac comb combined with a rectangular pulse, is considered a multiple exposure, even though the sensitivity never goes to zero during the exposure.

Exposure

In photography, exposure is the total amount of light allowed to fall on the photographic medium (photographic film or image sensor) during the process of taking a photograph. Exposure is measured in lux seconds, and can be computed from exposure value (EV) and scene luminance.

The "correct" exposure for a photograph is determined by the sensitivity of the medium used. For photographic film, sensitivity is referred to as film speed and is measured on a scale published by the International Organization for Standardization (ISO). Faster film requires less exposure and has a higher ISO rating. Exposure is a combination of the length of time and the level of illumination received by the photosensitive material. Exposure time is controlled in a camera by shutter speed and the illumination level by the lens aperture. Slower shutter speeds (exposing the medium for a longer period of time) and greater lens apertures (admitting more light) produce greater exposures.

An approximately correct exposure will be obtained on a sunny day using ISO 100 film, an aperture of f/16 and a shutter speed of 1/100th of a second. This is called the sunny 16 rule: at an aperture of f/16 on a sunny day, a suitable shutter speed will be one over the film speed (or closest equivalent).

Ultimately there is no such thing as "correct exposure", as a scene can be exposed in many ways, depending on the desired effect a photographer wishes to convey.

F-number

In optics, the f-number (sometimes called focal ratio, f-ratio, or relative aperture) of an optical system expresses the diameter of the entrance pupil in terms of the effective focal length of the lens. It is the quantitative measure of lens speed, an important concept in photography.

Film format

A film format is a technical definition of a set of standard characteristics regarding image capture on photographic film, for either stills or movies. It can also apply to projected film, either slides or movies. The primary characteristic of a film format is its size and shape.

In the case of motion picture film, the format may also encompass audio parameters (though often not). Other characteristics usually include the film gauge, pulldown method, lens anamorphosis (or lack thereof), and film gate or projector aperture dimensions, all of which need to be defined for photography as well as projection, as they may differ.

Film speed

Film speed is the measure of a photographic film's sensitivity to light. Stock with lower sensitivity (lower ISO speed rating) requires a longer exposure and is thus called a slow film, while stock with higher sensitivity (higher ISO speed rating) can shoot the same scene with a shorter exposure and is called a fast film.

In the first approximation the amount of light energy which reaches the film determines the effect on the emulsion, so that if the brightness of the light is multiplied by a factor and the exposure of the film decreased by the same factor so that the energy received is the same, the film will be exposed to the same density; this rule is called reciprocity, and the concept of a unique speed for an emulsion is possible because reciprocity holds. In practice this holds reasonably well for normal photographic films for the range of exposures usually used, say 1/1000 sec to 1 sec, but longer exposures, different for different films, are required outside these limits, a phenomenon known as reciprocity failure.

Perspective distortion

In photography and cinematography, perspective distortion describes one of two phenomena – the appearance of a part of the subject as abnormally large, relative to the rest of the scene, or an apparent lack of distance between objects in the foreground and those behind them.

Photographic printing

Photographic printing is the process of producing a final image for viewing, usually on sensitized paper from a previously prepared photographic negative.

The process consists of three major steps, performed in a photographic darkroom or within an automated photo printing machine:

1. Exposure of the image onto the sensitized paper using a contact printer or enlarger
2. Processing of the latent image through a multistep chemical immersion process.
1. Development of the exposed image.
2. Optionally Stopping development by neutralizing, diluting or removing developing agent.
3. Fixing the final print by dissolving remaining unexposed/undeveloped light-sensitive emulsion.
4. Washing thoroughly to remove chemicals used in processing, protecting the finished print from fading and decay.
3. If made on glossy paper, ferrotyping to enhance the reflective gloss.
4. Optional Toning of the print through additional chemical processes.
5. Texturing and drying of the final print.

Pinhole camera

A pinhole camera is a camera without a conventional glass lens. An extremely small hole in a very thin material can focus light by confining all rays from a scene through a single point. In order to produce a reasonably clear image, the aperture has to be about a hundred times smaller than the distance to the screen, or less. The shutter of a pinhole camera usually consists of a hand operated flap of some light-proof material to cover and uncover the pinhole. Pinhole cameras require much longer exposure times than conventional cameras because of the small aperture; typical exposure times can range from 5 seconds to hours or days.

The image may be projected on a translucent screen for real-time viewing (popular for viewing solar eclipses; see also camera obscura), or can expose film or a charge coupled device (CCD). Pinhole cameras with CCDs are sometimes used for surveillance work because of their small size.

Red-eye effect

The red-eye effect in photography is the common appearance of red eyes on photographs taken with a photographic flash when the flash is too close to the lens (as with most compact cameras).

Rule of thirds

The rule of thirds is a compositional rule of thumb in photography and other visual arts such as painting. The rule states that an image can be divided into nine equal parts by two equally-spaced horizontal lines and two equally-spaced vertical lines. The four points formed by the intersections of these lines can be used to align features in the photograph. Proponents of this technique claim that aligning a photograph with these points creates more tension, energy and interest in the photo than simply centering the feature would.

The photograph to the right demonstrates the application of the rule of thirds. The horizon sits at the horizontal line dividing the lower third of the photo from the upper two-thirds. The tree sits at the intersection of two lines, sometimes called a power point. Points of interest in the photo don't have to actually touch one of these lines to take advantage of the rule of thirds. For example, the brightest part of the sky near the horizon where the sun recently set does not fall directly on one of the lines, but does fall near the intersection of two of the lines, close enough to take advantage of the rule.

The application of the rule of thirds to photographs is considered by many to make them more aesthetically pleasing and professional-looking. The rule of thirds can be applied by lining up subjects with the guiding lines, placing the horizon on the top or bottom line instead of the center, or allowing linear features in the photograph to flow from section to section. In addition, many photographers recommend treating any "rule" of composition as more of a guideline, since pleasing photographs can often be made while ignoring one or more such rules.

Science of photography

Science of photography refers to the use of science, such as chemistry and physics, in all aspects of photography. This applies to the camera, its lenses, physical operation of the camera, electronic camera internals, and the process of developing film in order to take and develop pictures properly.

Shutter speed

In photography, shutter speed is the length of time a shutter is open; the total exposure is proportional to this exposure time, or duration of light reaching the film or image sensor.

Most factors that affect the total exposure include the scene luminance and the aperture size; photographers can trade off shutter speed and aperture by using units of stops. A stop up and down on each will halve or double the amount of light regulated by each; exposures of equal exposure value can be easily calculated and selected. For any given total exposure, or exposure value, a fast shutter speed requires a larger aperture (smaller f-number). Similarly, a slow shutter speed, a longer length of time, can be compensated by a smaller aperture (larger f-number).

Slow shutter speeds are often used in low light conditions, extending the time until the shutter closes, and increasing the amount of light gathered. This basic principle of photography, the exposure, is used in film and digital cameras, the image sensor effectively acting like film when exposed by the shutter.

Shutter speed is measured in seconds. A typical shutter speed for photographs taken in sunlight is 1/125th of a second. In addition to its effect on exposure, shutter speed changes the way movement appears in the picture. Very short shutter speeds are used to freeze fast-moving subjects, for example at sporting events. Very long shutter speeds are used to intentionally blur a moving subject for artistic effect.

Adjustment to the aperture controls the depth of field, the distance range over which objects are acceptably sharp; such adjustments generally need to be compensated by changes in the shutter speed.

In early days of photography, available shutter speeds were somewhat ad hoc. Following the adoption of a standardized way of representing aperture so that each major step exactly doubled or halved the amount of light entering the camera (f/2.8, f/4, f/5.6, f/8, f/11, f/16, etc.), a standardized 2:1 scale was adopted for shutter speed so that opening one aperture stop and reducing the shutter speed by one step resulted in the identical exposure.

Zone system

The Zone System is a photographic technique for determining optimal film exposure and development, formulated by Ansel Adams and Fred Archer in 1941. The Zone System provides photographers with a systematic method of precisely defining the relationship between the way they visualize the photographic subject and the final results. Although it originated with black and white sheet film, the Zone System is also applicable to roll film, both black and white and color, negative and reversal, and to digital photography.