Photography - Class News | Office Technology News



PhotographyPhotography is defined as the method of picture making based on principles of light, optics, and chemistry. The word “photography” comes from the Greek words photos meaning “light” and graphein meaning “to draw.” The scientist Sir John F. W. Herschel was the first to use the word in 1839. The first fixed image was obtained by Joseph Nicephore Niepce in 1827. At about the same time, Louis Jacques Mande Daguerre was experimenting with methods for capturing an image. Approximately twelve years later, Daguerre was able to reduce the exposure time to less than 30 minutes, ushering in the age of modern photography. Daguerre partnered with Niepce to improve the process Niepce developed to take the first permanent photograph. Daguerre developed an effective method of photography that he named after himself—the daguerreotype. Daguerreotypes were metal sheets on which a positive silver image was affixed. He and Niepce’s son sold the right for the daguerreotype to the French government.William Henry Fox Talbot, a contemporary of Daguerre, was the inventor of the first process using a negative to make multiple prints. Another medium, tintypes, was patented by Hamilton Smith. The tintype method used a thin sheet of iron to provide a base for light-sensitive material, producing a positive image.In 1889, George Eastman saw the potential for mass marketing and produced a newly invented film with a flexible and unbreakable base that could be rolled. Eastman sold simple cameras that contained factory-installed film. The photographer pushed a button to produce a negative and then, when the film was used up, mailed the camera back to the Kodak factory. At the factory, the film was removed from the camera and then processed and printed. The camera was reloaded with film and then returned to the owner.Color film, introduced in 1935, was commercially available beginning in the early 1940s. Color film used the technology of dye-coupled colors in which a chemical process connected the three dye layers together to create a color image.The Leitz Company in Germany introduced the Leica camera in 1925. It was one of the first cameras to use 35-millimeter film, which was small-sized film designed for motion pictures. The Leitz camera was light and compact and became popular with amateur and professional photographers.Camera BasicsPhotographs are taken by letting light into a light-sensitive medium, which records the image. A camera consists of a light-tight box that stores a light-sensitive device and a lens that magnifies and focuses the image onto the light-sensitive device through a hole in the box called the aperture. A shutter opens and closes when the user presses the shutter release, exposing the film to the light. Cameras share some of the following common features:Light-tight bodyLensLight-sensitive medium to capture the imageLens aperture, which controls the amount of light reaching the mediumShutter, which opens and closes to allow light to act for a specified timeViewfinder or screenSome additional camera features include a tripod screw of standard size to fit any tripod, a method for setting the distance, and a method for setting the film speed. Cameras vary in the amount of control a user has over the aperture, shutter, and distance settings, and whether these can be set automatically.Digital CamerasA digital camera is a camera equipped with an electronic photosensitive sensor that stores photographs in a digital format directly in the camera’s memory. The photographs can be downloaded to a computer. Some digital camera terminology includes white balance, pixel, ppi, and dpi.PixelsThe word pixel is a contraction of the term picture element. Digital images are made up of small squares. Each pixel in an image has a numerical value of 0 to 255 and is made up of three colors—red, green, and blue. Over 16 million combinations of colors are available with each one presenting a different color. A common method for categorizing digital cameras is in the number of pixel count. This represents the number of individual pixels that go into making each image. This number can range from approximately one million to 14 million or more. One million pixels equal one megapixel, which is written as MP. So, a 1MP digital camera has one million pixels and a 5MP camera has five million pixels.Aspect RatioMost digital cameras have an aspect ratio of 3:2. The aspect ratio is the width divided by the height of an image and is usually expressed as two integers. For example, width/height = 1.5 is expressed as width:height?= 3:2.White BalanceWhite balance is the process of removing unrealistic color casts so that objects appearing white in person appear white in a photograph. Camera white balance takes into account the “color temperature” of a light source, which is the relative warmth or coolness of white light. Our eyes are good at judging what is white under different light sources; however, digital cameras often have difficulty with auto white balance. With a digital camera, the user can pick the white balance to suit the light source, so that white looks white, not yellow or blue. Normally, a camera automatically determines the white balance setting to use. Most digital cameras have settings for sunlight, shade, electronic flash, fluorescent lighting, and tungsten lighting. Some have a manual or custom setting where the user points the camera at a white card and lets the camera figure out what setting to use to make it white. ................
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