PhotoPhase Digital Camera Back for Large Format Cameras – User's Guide
Section 1 The PhotoPhase Digital Camera Back
The PhotoPhase digital camera back for large format cameras will enable you to use your usual 4" x 5" large format cameras and lenses to take digital photographs in color. The camera back fits into a standard spring- back film loading mechanism, just like a normal camera back.
Section 1.1 How it Works
The camera back contains a light sensitive element called a CCD (charge coupled device). This device contains many tiny light sensitive areas, each of which maps to one pixel in the final photograph. A pixel is one picture element or picture cell, and is analogous to the grain size of film stock.
The camera back uses a sensor with three linear CCDs; there is one line for each additive primary color: red, green, and blue (RGB). Each line, or array, is one pixel high and 5000 pixels wide. In the final image, the three RGB lines are digitally mixed to produce a single line of pixels in full color.
Before exposure, called capturing in digital techniques, the image is focussed onto the plane in which the CCD array will travel. At the start of the capture process the array is positioned at the top of the area to be scanned. During capture, the RGB lines are read, the CCD sensor is moved a distance equal to the height of one pixel, and then the next lines are read. This is repeated until the entire image area has been covered. This process is called scanning.
The camera back contains the basic sensory electronics for image cap- ture (the CCD and analog to digital converter). The camera back also contains microprocessors which control the camera back, processes incoming images, and communicate with your computer. The Phase One software, running on the computer, makes it possible for you to calibrate and control the camera back, view your images, and make
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