Saturday, November 7, 2009

Capturing Light

Photography is the capturing of light that is focused by the camera lens onto a light sensitive medium. In the early days of photography the medium consisted of coated glass plate. Later, light sensitive film had been developed and was used for many decades in cameras of all sizes and formats. In the last decade the development of digital “film” cameras has overtaken conventional film cameras in the market place. A digital camera uses a light sensitive sensor to take small points of light and store them digitally (a string of ones and zeroes) on to a memory card. These points of light are referred to as pixels (a techno term for picture element). Each pixel records the intensity of the colors of Red, Green and Blue commonly referred to as RGB from that point of light. The RGB value is stored on a memory card in the camera and can later be transferred to a computer for editing and printing.

In the days of film the light sensitivity was an ISO value (International Organization for Standardization) and had a numeric value of 25, 100, 200, 400 etc. The lower the value the finer the grain of the film but it had a lower sensitivity to light. So there is a compromise to be had between how sharp you wanted the photo to be and how much light you had to capture the image with. Digital cameras have the same ability but with the same inherent effect of getting a grainer photo when shooting at high ISO values. Of course, with digital film processing there is a certain amount of editing that can compensate for some of these effects, but it is a good photographic practice to attempt to capture the best image you can within the camera and minimize the amount of post-processing that may be required.

Digital cameras are usually advertised by the amount of pixels they can capture, e.g. 10 or 12 mega pixels (mega = 1 million). So, a 12 mega pixel format may be 4000 pixels wide by 3000 pixels high. If you are printing at 300 dots per inch and each pixel was a dot then you could print a high resolution photo of approximately 13.3 inches by 10 inches. Do not confuse pixel quantity to the quality of a camera. While it is true that high quality cameras do have a larger amount of pixels they can use to capture a photo, it is not the only factor to consider when determining a camera’s quality. Many other factors are involved, such as the sensitivity of the photo sensor, the overall size of the photo sensor and lens quality. When it comes to lenses, look for the optical zoom factor. The greater the number the closer the lens can bring the image to the camera’s photo sensor yielding a higher resolution photo over using digital zoom within the camera.

Whatever camera you choose to use, the idea behind photography is capturing the essence of a scene, object or person at a particular point in time, environment and circumstance. So, in reality you are capturing the light either emitted or radiated at the fraction of a second that it takes to open and close the shutter on the camera. To me, there is a spiritual quality of doing that, for that fraction is gone for all of eternity except for what you were able to capture within your camera. In the early days of the west when photographers such as Remington, Curtis and others ventured out to photograph the places and inhabitants of that unknown region there was reluctance among the American Indians to be photographed. They feared that the photographer was taking their soul while photographing them. Perhaps, they were not wrong, a good photograph captures the essence of a being and being spiritual beings does capture a bit of our souls at that precise moment in the overall continuum of time.

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