10 Most Amazing Pictures DefinitionSource(Google.com.pk)
causing great surprise or sudden wonder
"Photographic" redirects here. For other uses, see Photography (disambiguation).
Photography (derived from the Greek photos- for "light" and -graphos for "drawing") is the art, science, and practice of creating durable images by recording light or other electromagnetic radiation, either chemically by means of a light-sensitive material such as photographic film, or electronically by means of an image sensor. 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. The result in an electronic image sensor is an electrical charge at each pixel, which is electronically processed and stored in a digital image file for subsequent display or processing.
The result in a photographic emulsion is an invisible latent image, which is later chemically developed into a visible image, either negative or 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 enlarger or by contact printing.
Photography has many uses for business, science, manufacturing (e.g. photolithography), art, recreational purposes, and mass communication.
The snapshot—taken by astronauts on December 7, 1972, at 5:39 a.m. EST (10:39 UTC)—is one of the most widely distributed photographic images in existence. The image is one of the few to show a fully illuminated Earth, as the astronauts had the Sun behind them when they took the image. To the astronauts, Earth had the appearance and size of a glass marble, hence the name.
The photograph was taken about 5 hours and 6 minutes after launch of the Apollo 17 mission, and about 1 hour 54 minutes after the spacecraft left its parking orbit around the Earth, to begin its trajectory to the Moon. The time of Apollo 17's launch, 12:33 a.m. EST, meant that Africa was in daylight during the early hours of the spacecraft's flight. With the December solstice approaching, Antarctica was also illuminated.
The Blue Marble photograph in its original orientation
1967 image from ATS-3 satellite
An Indian Ocean cyclone can be seen in the top right of the image. This storm had brought flooding and high winds to the Indian state of Tamil Nadu on December 5, two days before the photograph was taken.
The photograph's official NASA designation is AS17-148-22727. (NASA photograph AS17-148-22726, taken just before and nearly identical to 22727, is also used as a full-Earth image.) The photograph was originally oriented with the south pole at the top, with the island of Madagascar visible just left of center, and the continent of Africa at its right. However, the image was turned upside-down to fit the traditional view.
The photographer used a 70-millimetre Hasselblad camera with an 80-millimetre lens. NASA officially credits the image to the entire Apollo 17 crew – Eugene Cernan, Ronald Evans and Jack Schmitt – all of whom took photographs during the mission with the on-board Hasselblad. Although the identity of the actual photographer remains unknown, evidence examined after the mission suggests that it was likely Jack Schmitt.