Tuesday 28 April 2015

Digital photography

In 1981, Sony unveiled the first consumer camera to use a charge-coupled device for imaging, eliminating the need for film: the Sony Mavica. While the Mavica saved images to disk, the images were displayed on television, and the camera was not fully digital. In 1991, Kodak unveiled the DCS 100, the first commercially available digital single lens reflex camera. Although its high cost precluded uses other than photojournalism and professional photography, commercial digital photography was born.
Digital imaging uses an electronic image sensor to record the image as a set of electronic data rather than as chemical changes on film. An important difference between digital and chemical photography is that chemical photography resists photo manipulation because it involves film and photographic paper, while digital imaging is a highly manipulative medium. This difference allows for a degree of image post-processing that is comparatively difficult in film-based photography and permits different communicative potentials and applications.
Digital photography dominates the 21st century. More than 99% of photographs taken around the world are through digital cameras, increasingly through smartphones.

Development of chemical photography

Around the year 1800, Thomas Wedgwood made the first known attempt to capture the image in a camera obscura by means of a light-sensitive substance. He used paper or white leather treated with silver nitrate. Although he succeeded in capturing the shadows of objects placed on the surface in direct sunlight, and even made shadow-copies of paintings on glass, it was reported in 1802 that "the images formed by means of a camera obscura have been found too faint to produce, in any moderate time, an effect upon the nitrate of silver." The shadow images eventually darkened all over because "no attempts that have been made to prevent the uncoloured part of the copy or profile from being acted upon by light have as yet been successful." Wedgwood may have prematurely abandoned his experiments due to frail and failing health; he died aged 34 in 1805.The oldest surviving permanent photograph of the image formed in a camera was created by Niépce in 1826 or 1827. It was made on a polished sheet of pewter and the light-sensitive substance was a thin coating of bitumen, a naturally occurringpetroleum tar, which was dissolved in lavender oil, applied to the surface of the pewter and allowed to dry before use.Nineteenth-century experimentation with photographic processes frequently became proprietary. The German-born, New Orleans photographer Theodore Lilienthal successfully sought legal redress in an 1881 infringement case involving his "Lambert Process" in the Eastern District of Louisiana.

History of photography


The history of photography has roots in remote antiquity with the discovery of the principle of the camera obscura and the observation that some substances are visibly altered by exposure to light. As far as is known, nobody thought of bringing these two phenomena together to capture camera images in permanent form until around 1800, when Thomas Wedgwoodmade the first reliably documented although unsuccessful attempt. In the mid-1820s, Nicéphore Niépce succeeded, but several days of exposure in the camera were required and the earliest results were very crude. Niépce's associate Louis Daguerre went on to develop the daguerreotype process, the first publicly announced photographic process, which required only minutes of exposure in the camera and produced clear, finely detailed results. It was commercially introduced in 1839, a date generally accepted as the birth year of practical photography.
World's earliest surviving camera photograph, 1826 or 1827



Introduction

Photography is the scienceart and practice of creating durable images by recording light or other electromagnetic radiation, either electronically by means of an image sensor, or chemically by means of a light-sensitive material such asphotographic film.
Typically, a lens is used to focus the light reflected or emitted from objects into a real image on the light-sensitive surface inside a camera during a timed exposure. With an electronic image sensor, this produces an electrical charge at each pixel, which is electronically processed and stored in a digital image file for subsequent display or processing. The result withphotographic emulsion is an invisible latent image, which is later chemically "developed" into a visible image, either negativeor positive depending on the purpose of the photographic material and the method of processing. A negative image on film is traditionally used to photographically create a positive image on a paper base, known as a print, either by using an enlargeror by contact printing.
Photography is employed in many fields of science, manufacturing (e.g. photolithography) and business, as well as its more direct uses for art, recreational purposes, and mass communication.ggggggggggggggggggggggggggggf