Reported July 2005

BACKGROUND: One lone physicist hopes to create an ultra-high-resolution portrait of America by taking a series of gigapixel images with his own custom camera created from parts of old spy planes and nuclear reactors. Each image fills an entire DVD with data.

HOW CAMERAS WORK: Photography essentially freezes a moment in time by recording the visible light reflected from the objects in the camera lens's field of view. The reflected light causes a chemical change to the film inside the camera, which is coated with grains of silver-halide crystals. These crystals are naturally sensitive to light. By opening a camera's shutter for a split second, you expose the crystals to light and transfer energy from the photons to the silver halide crystals. This induces the chemical reaction, forming a latent image of the visible light reflected off the objects in the viewfinder.

WHAT ARE PIXELS: "Pixel" is short for picture element, and represents a single point in a graphic image. Graphics monitors display images by dividing the screen into thousands (or millions) of pixels, arranged in rows and columns. A megapixel equals one million pixels. Pixels are a measure of digital image quality: the more pixels, the better. The modern digital camera works on the same principle as a conventional camera, but instead of focusing light onto a piece of film, it focuses it onto an image sensor array -- called a charged coupled device (CCD) -- made of tiny light-sensitive diodes that convert light into electrical charges. It turns the fluctuating waves of light (analog data) into bits of digital computer data. The more sensors that are packed onto the CCD's surface, the higher the pixel count, and the higher the resolution of the final image.

CUSTOMIZATION: Flint has built a large-format camera, the same used in military spy planes, filled with large rolls of high-resolution film typically used for aerial photography and geological surveys. His custom-designed lenses are mounted with screws and dials that can be adjusted to within one thousandth of an inch. To focus his lens accurately, Flint measures the distance to every major object in the field of view with a laser range finder, then calculates how to adjust the screws.

The Optical Society of America contributed to the information contained in the TV portion of this report.

If you would like more information, please contact:

Optical Society of America
2010 Massachusetts Ave., N.W.
Washington, D.C. 20036.1023
(202) 223-8130

info@osa.org
http://osa.org/

Graham Flint

Did you know...

Graham Flint's giant photographs have appeared at San Francisco's Exploratorium, and San Diego's Museum of Photographic Arts will display eight or nine of them this summer.