Реферат на тему Digital Imaging And Their Effects Essay Research
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Digital Imaging And Their Effects Essay, Research Paper
The Process and Difference of Digital Imaging and Their Effects
The traditional photographic process that has defined image reproduction for over 150 years involves a long drawn out series of chemical reactions beginning with the capture of light on silver film and ending with the fixing of the image onto paper or a transparency through the development processing. The final image is analog, which means it is composed of continuous gradients that are analogous to the gradients seen in the world around us.
Digital imaging, however, requires a completely different process. The image must be captured electronically on a light sensitive silicon chip. Each silicon chip contains thousands of pixels, which is “picture” plus “element”, which measure light, color, and contrast. Because each pixel is a square and uniform in dimension, each individual one can be changes by means of a computer. The size of each pixel is determined by the resolution, which is the number of pixels per square inch. The key difference between an image on film and a digital image is the resolution. For example, when you look at a painting, you see many separate pixels that form the whole painting to form a conceptual process. When thousands of pixels are formed together in a digital image, you form one single image that leads you to view the photograph as a single view. In 1995 Kodachrome film had a resolution equivalent to 18 million pixels, the best digital camera had a resolution less than one tenth of this. As this capability continues to grow and improve, however, other means of digitizing photographs have become the medium choice for altering images. If an image is analog to begin with, it must me converted to a digital form, hence turning it into a series of 0?s and 1?s that a computer can read. A scanning device does this, before the image can be read on screen. When turning an analog image into a digital image, it changes the process of development from chemical to mathematical, because each pixel is represented my a number and stored in the computers memory for easy reading. This process makes the image true and impossible to tell how many duplicates of the image have been made.
Once information is in its digital form, it becomes very simple to save, alter, and duplicate. Because each pixel can be enlarged and changed on the computer screen, each piece of the image can be altered at will. Elements can be added or subtracted, changed in color, brightness, or contrast. Areas of the picture can be copied and moved to other areas of the image where other things have been removed, and this can be repeated indefinitely. People can be made fatter or thinner, the color of hair and eyes can be changes, or completely removed from a picture is so desired. When the image is finished, it can be printed or sent via telephone lines or satellite anywhere in the world.
Traditional photographs may be altered in four basic ways: in the set up of the model, camera, and lighting before the photograph is taken; in the way the photograph is taken; in the processing of the film; or by the addition or deletion of elements to the processed photograph, followed by retouching the whole image. Portrait photographers are especially adept at setting up the scene and subject so that it will appear in the most flattering light. Light sources such as from a fire; candle, neon tubes, or incandescent bulbs can dramatically alter the way we interpret personalities. Shadows can be filled in or deepened. Angles are carefully chosen, and subjects are positioned so the camera only sees their good side. Subjects can be places in front of any backdrop to convince the viewer of the subjects where about. It has been believed that historical photographs that have been found have been staged because the set up or subjects suggest image manipulation.
One famous example is photographs of the Civil War taken in 1863 by Alexander Gardner, where the same dead soldier in rebel uniform is seen behind a wall of piled stones nearly enclosed by a big rock foundations, his musket is still standing, and then again as a Northern soldier in a field, with a gun lying beside his head. Clearly the same corpse has been used twice for an aesthetic and editorial effect.
After the set-up is done, various other schemes can be used to further manipulate the image. In addition to warm diffused light or strident lighting, the camera lens can romanticize the subject through soft focus or “harden” the subject through sharp focus. Different focal lenses can bring the background into clarity. With a wide-angle lens, the field takes on equal importance to the subject or even comments on the foreground figure. They can flatten or blur the background into insignificance with a telephoto lens that has very shallow depth of field, which directly puts all the emphasis on the subject. Full color can make an image seem happy and festive compared to an image in black and white that would be depressing. Angle and distance have powerful connotations for emotional involvement and attitude towards the subject. The composition and what is included in the picture and what is left out can also deeply alter a person?s perception of the whole image. Before any photograph is taken, therefore, a number of decisions have already affected the outcome of the final photograph.
This is why it is said so often that there is no such thing as an objective photograph. The photographer already builds the attitude and tone and mood into the photograph. The only photography that avoids these rules are passport photography and photography done by police because of a crime. In these two instances, things are seen just as they are and minimize the photographer?s discretion and ensure uniformity.
In the processing and post-processing stages, a variety of techniques can be used to alter the print, including over or underexposure or treating the negative to cover lines or remove unwanted objects or people from the image. If arts are masked off or cut out of the photograph, the natural gradients of the photograph are disturbed and an unnatural sharp edge appears in the final image. Because when the film is developed, the clumping of molecules forms an emulsion grain, if this grain is subsequently disturbed by pen, pencil, or paint, or a specific section is erased the alteration is easily detectable. If parts are added to a photograph after it is developed, they must match exactly before the composite can be convincingly rephotographed. Because any difference in proportion, color, brightness, focus, contrast, lighting, or camera angle is an immediate perceptual signal. Any additions must be photographed under nearly exact conditions as the primary photograph and reflect the exact position from which it would have naturally occurred.
Even when altered photographs are rephotographed, alterations such as retouching and montages never disappear entirely because traditionally photography is an analog representation and therefore difficult to alter without obvious effect. Unlike a digital image, which is broken down into small separate units, the traditionally processed photograph appears as a continuous unbroken sequence of subtle gradients. This makes it extremely difficult to rework a photograph because there are no individual units or cells in a grid, from which to work with after the image is fixed. There are only ever increasingly and subtle gradations that are nearly impossible to retouch convincingly. The final image?s surface is so smooth and clear that retouching would be very obvious.
To “fake” a photograph it is necessary to have mastered all of the skills in doing so. Otherwise, it will be even easier to detect the falsehood of the photograph. A photograph that has been faked must have all the aspects of a real photograph to be believed as real, every shadow and highlight, and the notion that the photograph is a realistic possibility. Many experts may often disagree on a photograph?s authenticity, but many have to go through a lot of research and many looks to determine if an image is untrue. The first thing someone may question when inquiring about a possible fake is why was the image taken. When it comes to photo “fakery”, money is usually the key element in the answer to this question. After the initial questioning, a number of different experts are used; including: photo interpreters, subjective experts, photogrammetrists, chemical analysts, paper analysts, and technologists. But even the most intense studies can not always detect a bogus photograph. Some pictures have not been labeled as real or fake for many years.
The famous Hemingway quotes “a picture is worth a thousand words”, is exactly what artistic photographers may try and capture in their images. It is the story below the surface of the photograph that they trying to express. They seek to record the critical moment that implies a larger reality. But then on the other hand you have tabloid photographers and people putting images on the internet, that decide on their own behalf to change the view of the photograph and its meaning to those who see it.
It is exactly these situations and the issues of copyright that hurt the photography profession and integrity. The use of computers has benefited mankind a great deal, but it is its misuse that is harming the professionalism. These issues are hosts a whole new lot of legal questions. How many changes can be made without altering the original integrity of the photo? When a photo is made from several different photographs to whom is the copyright owned? And when several people have access to the original photograph, it makes it even more difficult to claim the rights of ownership. Besides of the protection of the photographer, the subjects I the image are neglected as well. Each person has become vulnerable to the fact that if their picture is taken they run the risk of being misrepresented somewhere down the line, may it be from the photographer or by someone else who has access to the image. It is for this reason why photographers now must be so specific with model releases and the written words in the model release, so in the long run the photographer is not responsible for the misuse of the image. For example if the image is placed on the internet as part of a news story or a portfolio piece, any person may be able to copy that right from their computer screen and do whatever they please with it. It is that difficult to protect the images of professional photographers and their property.
It is in my opinion that image manipulation can be as much destructive as it its beneficial. As each image is produced, it is one more image in the world that can be changed for the better or for the worse. I believe that it is the photographer?s discretion, with the permission of each of their subjects, to manipulate in an agreeable manner to all those involved. Any other uses of a photograph by anyone else but the original owner should be used only with permission to do so and when the owner knows what the exact use will be. Photography is an amazing tool that has so many uses and purposes it is uncountable. It is a shame that as technology progresses, as it will continue to do for the rest of time, that it can be used in a harmful and deceitful way. Surprisingly, photo manipulation has been around since the beginning of photography itself. We now live in a world where photography doesn?t stop at the photograph, it is now a phenomenon known as digital imagery and it will be with us for the rest of time, and only getting better and harder to detect as time goes on. The speed of improvement on this technology is moving so fast that few can get a hold on it, including the lawmakers to protect the photographers and their subjects. Hopefully for the sake of the humanity, it will gain control and turn us all into believers of the images we see rather than doubters and skeptics.
Bibliography
Bibiliography
1. Brugioni, Dino A. Photo Fakery. Copyright 1999, Library of Congress Cataloging-In-Publication Data.
2. Gross, Larry; Katz, John Stewart; Ruby Jay. Image Ethics. Copyright 1988, Oxford University Press.
3. Seward Barry, Ann Marie. Visual Intelligence. Copyright 1998, State University of New York Press, Albany.
4. World Wide Web. www.jupiter.com www.photonews.com
Bibiliography
1. Brugioni, Dino A. Photo Fakery. Copyright 1999, Library of Congress Cataloging-In-Publication Data.
2. Gross, Larry; Katz, John Stewart; Ruby Jay. Image Ethics. Copyright 1988, Oxford University Press.
3. Seward Barry, Ann Marie. Visual Intelligence. Copyright 1998, State University of New York Press, Albany.
4. World Wide Web. www.jupiter.com www.photonews.com
Bibiliography
1. Brugioni, Dino A. Photo Fakery. Copyright 1999, Library of Congress Cataloging-In-Publication Data.
2. Gross, Larry; Katz, John Stewart; Ruby Jay. Image Ethics. Copyright 1988, Oxford University Press.
3. Seward Barry, Ann Marie. Visual Intelligence. Copyright 1998, State University of New York Press, Albany.
4. World Wide Web. www.jupiter.com www.photonews.com