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Photography - interesting facts about photography

In this article we will talk about principles of a classical photo - that which train at best photography schools. A photograph is taken with a camera by pressing a button which opens a shutter in the glass lens for a fraction of a second. Light passes through the lens and forms an image on the film inside the camera. The shutter speed and the aperture (f-number) of the diaphragm inside the lens must be correctly set to take a good picture. An exposure meter can be used to measure the light and get the correct settings. The camera must also be properly focused to get a sharp picture.

Interesting facts about photography: The Polaroid Land J66 Camera - best photography schools

Interesting facts about photography: Agfa miniature camera - best photography schools

Interesting facts about photography:

The Polaroid Land J66 Camera in use. Ten seconds after moving the film on, the print can be lifted out

Interesting facts about photography:

An Agfa miniature camera showing various adjustments. The aperture is set at stop f8 and the lens is focused on an object ten feet away. The marks opposite the f8 positions on the depth of field scale, show that the depth of field is from 8 to 15 feet

The film is a long, transparent plastic (cellulose acetate) strip covered with a light-sensitive coating called an emulsion. The emulsion is made up of minute grains of silver bromide and iodide in gelatin. When light falls on the silver salts, they change chemically according to the amount of light falling on them. In this way, they record the scene being photographed.

A visible image of the scene is obtained by treating the silver salts with chemicals. This process is called developing. First the film is put into a developer, a solution which changes the exposed salts into metallic silver. The exposed areas therefore become dark. Then the film is washed in water (the stop bath) to remove excess developer.

Next, the film is treated with a fixing solution, usually sodium thiosulphate, to remove the unexposed silver salts. The unexposed areas are therefore transparent. After washing and drying, the film holds a permanent, visible image.

But the image is the reverse of the scene photographed. Bright areas in the scene, which reflected much light into the camera, are developed to dark patches of silver. Dark areas in the scene, which reflected little light, become almost transparent. This reversed image is called a negative.

The negative is changed into a positive image by the process of printing. In printing, a bright light is shone through the negative onto a piece of printing paper, which has a light-sensitive emulsion like a film. In the same way as before, the image formed is developed to produce a reverse image of the negative. Reversing the negative, of course, reproduces the original scene. The simplest method of printing is contact printing, in which print and negative are in contact. But larger prints can be produced by enlarging. An en-larger throws a magnified image of the negative onto the paper.

Interesting facts about photography: color films are more complicated and more difficult to process than black-and-white films, but they are just as easy to take. There are two kinds of color film - negative and positive, or reversal. Color negative film produces colored prints. Color reversal film produces colored transparencies, or slides, which are viewed through a projector.

Color photography depends upon the feet that all colors can be produced by mixing blue, green and red lights. Color film has three layers of emulsion sensitive to blue, green and red light respectively. Processing involves developing and dyeing the images in each layer.

Remembering a few simple principles helps in taking good photographs. Don't always place the main subject in the center of the picture, or have the horizon running across the center. Move them to one side. In distant views, try to get something interesting in the foreground. Don't pose family groups with people staring at the camera. Get them to behave naturally and try to take them when they are not looking. Be careful not to get your shadow in the picture, and remember that pictures taken into the sun often look very beautiful.

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