Canon FS 3.6 - Manual (Page 32)

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Step 2 • Scanning
Scanned at
360 dpi
Image size = 10” x 10”
Output resolution changed to 720 dpi
Output magnification = 50%
Image size = 5” x 5”
4”
6“
Scan Resolution
= 360 dpi
Output Resolution = 180 dpi
Output Magnification = 200%
Output Resolution = 720 dpi
Output Magnification = 50%
12”
8”
2”
3”
Selecting Resolution and Magnification Settings
About Resolution and Magnification
The scanner reads the images on a film as a collection of dots that are assigned
values for brightness and tone. The density of these dots is referred to as the
resolution, and the resolution at which a film is scanned is called the scan
resolution.
The scan resolution should not be confused with the output resolution, which
determines the appearance of an image on a monitor or when output to a printer.
The ratio of the scan resolution to the output resolution is called the output
magnification. When both the scan and output resolution are the same, the
scanned image size and the output are the same size. When the output resolution
is lower than the scan resolution, the image is magnified, and when it is higher, the
image is reduced.
Why does the image size change with the magnification? Let us answer with
an example having the output resolution set to printer (720 dpi). If you set the
scan resolution to 360 dpi (a magnification factor of 50%), the image will
shrink because only 360 dots are scanned per inch while 720 are required to
match the specification for the output resolution. The image size changes
because the density has been increased without a corresponding increase in
the number of scanned dots.