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Tuesday, November 13, 2007

Commercial Photography

Manual shutter control and exposure settings can achieve unusual results

The commercial photographic world can be broken down to:

-Advertising photography: photographs made to illustrate and usually sell a service or product. These images are generally done with an advertising agency, design firm or with an in-house corporate design team.

-Fashion and glamour photography: This type of photography usually incorporates models. Fashion photography emphasizes the clothes or product, glamour emphasizes the model. Glamour photography is popular in advertising and in men's magazines. Models in glamour photography may be nude, but this is not always the case.

-Crime Scene Photography: This type of photography consists of photographing scenes of crime such at robberies and murders. A black and white camera or an infrared camera may be used to capture specific details.

-Still life photography usually depicts inanimate subject matter, typically commonplace objects which may be either natural or man-made.

-Food photography can be used for editorial, packaging or advertising use. Food photography is similar to still life photography, but requires some special skills.

-Editorial photography: photographs made to illustrate a story or idea within the context of a magazine. These are usually assigned by the magazine.

-Photojournalism: this can be considered a subset of editorial photography. Photographs made in this context are accepted as a documentation of a news story.

-Portrait and wedding photography: photographs made and sold directly to the end user of the images.

-Fine art photography: photographs made to fulfill a vision, and reproduced to be sold directly to the customer.

-Landscape photography: photographs of different locations made to be sold to tourists as postcards

The market for photographic services demonstrates the aphorism "one picture is worth a thousand words," which has an interesting basis in the history of photography. Magazines and newspapers, companies putting up Web sites, advertising agencies and other groups pay for photography.

Many people take photographs for self-fulfillment or for commercial purposes. Organizations with a budget and a need for photography have several options: they can assign a member of the organization or hire someone to shoot exactly what they want, run a public competition, or obtain rights to stock photographs either through traditional stock giants, such as Getty Images, Corbis, or through smaller microstock agencies, such as Fotolia.

Colour Photography

Early color photograph taken by Prokudin-Gorskii(1915)


Colour photography was explored beginning in the mid 1800s. Early experiments in color could not fix the photograph and prevent the color from fading. The first permanent color photo was taken in 1861 by the physicist James Clerk Maxwell.

One of the early methods of taking color photos was to use three cameras. Each camera would have a color filter in front of the lens. This technique provides the photographer with the three basic channels required to recreate a color image in a darkroom or processing plant. Russian photographer Sergei Mikhailovich Prokudin-Gorskii developed another technique, with three color plates taken in quick succession.

Practical application of the technique was held back by the very limited color response of early film; however, in the early 1900s, following the work of photo-chemists such as H. W. Vogel, emulsions with adequate sensitivity to green and red light at last became available.

The first color plate, Autochrome, invented by the French Lumière brothers, reached the market in 1907. It was based on a 'screen-plate' filter made of dyed dots of potato starch, and was the only color film on the market until German Agfa introduced the similar Agfacolor in 1932. In 1935, American Kodak introduced the first modern ('integrated tri-pack') color film, Kodachrome, based on three colored emulsions. This was followed in 1936 by Agfa's Agfacolor Neue. Unlike the Kodachrome tri-pack process the color couplers in Agfacolor Neue were integral with the emulsion layers, which greatly simplified the film processing. Most modern color films, except Kodachrome, are based on the Agfacolor Neue technology. Instant color film was introduced by Polaroid in 1963.

As an interesting side note, the inventors of Kodachrome, Leopold Mannes and Leopold Godowsky, Jr. were both accomplished musicians. Godowsky was the brother-in-law of George Gershwin and his father was Leopold Godowsky, one of the world's greatest pianists.
Color photography may form images as a positive transparency, intended for use in a slide projector or as color negatives, intended for use in creating positive color enlargements on specially coated paper. The latter is now the most common form of film (non-digital) color photography owing to the introduction of automated photoprinting equipment.

Black and White

"Casting Winds" - this black & white displays the classic monochrome look, as well as the use of simulated optical filtering (wratten #25) to enhance or diminish the rendering of certain light wavelengths.

All photography was originally monochrome, or black-and-white. Even after color film was readily available, black-and-white photography continued to dominate for decades, due to its lower cost and its "classic" photographic look. In modern times, black-and-white has mostly become a minority art form, and most photography has become color photography.
Many photographers continue to produce some monochrome images. Some full color digital images are processed using a variety of techniques to create black and whites, and some cameras have even been produced to exclusively shoot monochrome.

Monday, November 12, 2007

History

Nicéphore Niépce's earliest surviving photograph, c. 1826. This image required an eight-hour exposure, which resulted in sunlight being visible on both sides of the buildings.
Photography is the result of combining several technical discoveries. Long before the first photographs were made, Ibn al-Haytham (Alhazen) (965–1040) invented the camera obscura and pinhole camera, Albertus Magnus (1193–1280) discovered silver nitrate, and Georges Fabricius (1516–1571) discovered silver chloride. Daniel Barbaro described a diaphragm in 1568. Wilhelm Homberg described how light darkened some chemicals (photochemical effect) in 1694. The fiction book Giphantie (by the French Thiphaigne de La Roche, 1729-1774) described what can be interpreted as photography.

Photography as a usable process goes back to the 1820s with the development of chemical photography. The first permanent photograph was an image produced in 1826 by the French inventor Nicéphore Niépce. However, the picture took eight hours to expose, so he went about trying to find a new process. Working in conjunction with Louis Daguerre, they experimented with silver compounds based on a Johann Heinrich Schultz discovery in 1724 that a silver and chalk mixture darkens when exposed to light. Niépce died in 1833, but Daguerre continued the work, eventually culminating with the development of the daguerreotype in 1839.

Meanwhile, Hercules Florence had already created a very similar process in 1832, naming it Photographie, and William Fox Talbot had earlier discovered another means to fix a silver process image but had kept it secret. After reading about Daguerre's invention, Talbot refined his process so that it might be fast enough to take photographs of people. By 1840, Talbot had invented the calotype process, which creates negative images. John Herschel made many contributions to the new methods. He invented the cyanotype process, now familiar as the "blueprint". He was the first to use the terms "photography", "negative" and "positive". He discovered sodium thiosulphate solution to be a solvent of silver halides in 1819, and informed Talbot and Daguerre of his discovery in 1839 that it could be used to "fix" pictures and make them permanent. He made the first glass negative in late 1839.

In 1851, Frederick Scott Archer published his findings in "The Chemist" on the wet plate Collodion process. This became the most widely used process between 1852 and the late 1880s when the dry plate was introduced. There are three subsets to the Collodion process; the Ambrotype (positive image on glass), the Ferrotype or Tintype (positive image on metal) and the negative which was printed on Albumen or Salt paper.

Many advances in photographic glass plates and printing were made in through the nineteenth century. In 1884, George Eastman developed the technology of film to replace photographic plates, leading to the technology used by film cameras today.

Photographic Cameras

The camera or camera obscura is the image-forming device, and photographic film or a silicon electronic image sensor is the sensing medium. The respective recording medium can be the film itself, or a digital electronic or magnetic memory.

Photographers control the camera and lens to "expose" the light recording material (such as film) to the required amount of light to form a "latent image" (on film) or "raw file" (in digital cameras) which, after appropriate processing, is converted to a usable image. Modern digital cameras replace film with an electronic image sensor based on light-sensitive electronics such as charge-coupled device (CCD) or complementary metal-oxide-semiconductor (CMOS) technology. The resulting digital image is stored electronically, but can be reproduced on paper or film.
The controls usually include but are not limited to the following:

Focus of the lens
Aperture of the lens – adjustment of the iris, measured as f-number, which controls the amount of light entering the lens. Aperture also has an effect on focus and depth of field, namely, the smaller the opening [aperture], the less light but the greater the depth of field--that is, the greater the range within which objects appear to be sharply focused.

Shutter speed – adjustment of the speed (often expressed either as fractions of seconds or as an angle, with mechanical shutters) of the shutter to control the amount of time during which the imaging medium is exposed to light for each exposure. Shutter speed may be used to control the amount of light striking the image plane; 'faster' shutter speeds (that is, those of shorter duration) decrease both the amount of light and the amount of image blurring from subject motion or camera motion.

White balance – on digital cameras, electronic compensation for the color temperature associated with a given set of lighting conditions, ensuring that white light is registered as such on the imaging chip and therefore that the colors in the frame will appear natural. On mechanical, film-based cameras, this function is served by the operator's choice of film stock. In addition to using white balance to register natural coloration of the image, photographers may employ white balance to aesthetic end, for example white balancing to a blue object in order to obtain a warm color temperature.

Metering – measurement of exposure at a midtone so that highlights and shadows are exposed according to the photographer's wishes. Many modern cameras feature this ability, though it is traditionally accomplished with the use of a separate light metering device.

ISO speed – traditionally used to set the film speed of the selected film on film cameras, ISO speeds are employed on modern digital cameras as an indication of the system's gain from light to numerical output and to control the automatic exposure system. A correct combination of ISO speed, aperture, and shutter speed leads to an image that is neither too dark nor too light.

Auto-focus point – on some cameras, the selection of a point in the imaging frame upon which the auto-focus system will attempt to focus. Many Single-lens reflex cameras (SLR) feature multiple auto-focus points in the viewfinder.

Photography


Photography is the process of recording pictures by means of capturing light on a light-sensitive medium, such as a film or electronic sonsor. Light patterns reflected or emitted from objects expose a sensitive silver halide based chemical or electronic medium during a timed exposure, usually through a photographic lens in a device known as a camera that also stores the resulting information chemically or electronically.
The word "photography" comes from the French photographie which is based on the Greek words φως phos ("light"), and γραφίς graphis ("stylus", "paintbrush") or γραφή graphê ("representation by means of lines" or "drawing"), together meaning "drawing with light." Traditionally, the product of photography has been called a photograph, commonly shortened to photo.