5.1.6.2 <M> Magnification
The magnification (maximum physical resolution) is set by the distance of the camera from the window. The closer the camera is to the window, the high the resolution. The farther the camera is from the window, the lower the resolution.
Adjusting the magnification is a tedious and lengthy process; however, it is only necessary when you replace a camera board. The camera board is a simple and very reliable circuit that will rarely need replacement.
For testing magnification, this option scans precisely drawn lines on a test chart and calculates the distance between them as perceived by the scanner. This value is then compared to the actual known value.
Each CCD camera contains an array of 5312 pixels. When operating within specification, each camera should detect at least 5100 pixels. The end camera CCD arrays are electronically truncated to stay within the active scan area.
The status and prompt line allows you to see what the current settings are, the following key actions will allow you to change the settings.
Press <C> to select the number of the camera you wish to check. Then, enter the camera number (0 to 7, with the highest number dependent on the resolution of your scanner).
Press <T> to toggle between the two choices for sampling the signal. "Single" will take a sample when the space bar is pressed. "Auto" will sample continuously.
Press <R> to toggle between the two choices for reporting information.
•The "Short" report will display the number of pixels within the target.
•The "Long" report will list the following items: (1) the memory address in which the start of each line is recorded; (2) the width of each line in mils, along with whether that measurement is good, too wide, or too narrow, and (3) a summary of information including the memory address where the beginning of the first "good" or complete bar was noted and stored, and the distance or difference between the two addresses translated into a decimal number of pixels.
Press the Up and Down arrows to adjust the threshold. The Threshold is a number used to decide whether to classify pixels as black (a mark) or white (background). The threshold range is