The higher the scanning resolution, the finer the details that will be present in the resulting image. Of course, as resolution increases, the size of the file needed to store it increases, too. The optimum resolutions to scan and display coins depend on factors considered below. When you double the scanning resolution, say from 150 to 300 dpi, the result is four times as many pixels. Monitor Resolution Computer monitors display many thousands of pixels.
Monitor resolutions vary from one computer to another and are even configurable on some machines.
In many cases, monitor resolution is at or near 72 dpi. Because monitor resolution varies from one computer to another, the physical size of a given image also varies between the machines. An image that is 72 pixels wide and 72 pixels high will be displayed in a one inch by one inch square when the monitor resolution is 72 dpi. On another computer with a monitor resolution of 100 dpi, the same image will appear smaller, because the pixels are spaced closer together. The very important point here is that the width and height of an image may be substantially different when viewed on a different computer or when printed .