Line Screens; Scanner Resolutions - Xante Accel-a-Writer 8200 User Manual

Keep in mind that the higher the lines per inch, the tighter the screen
on the image will be. To produce higher levels of gray without using
a lower line screen, you must print at a higher dpi. An illustration of
this would be to print the same image at the Accel-a-Writer 8200's
optional 800 dpi with the same 60 line screen. You would now have
approximately 170 levels of gray (800/60=13; 13 x 13 + 1 = 170).
Use the following table as a guide to get 256 levels of gray.
LPI To Achieve 256 Levels of Gray
Printer
Resolution
1200 x 1200 dpi
800 x 800 dpi
600 x 600 dpi

Line Screens

Knowing how many levels of gray you would like to achieve is one
factor in determining the appropriate line screen to use. Depending
on the individual image quality, some degree of experimentation
usually is necessary to produce the best possible output. You do not
always have to achieve 256 levels of gray for the best output. We
have found the following line screens (lpi) to work the best: 60 for
600 dpi, 71 for 800 dpi, and 95 for 1200 dpi. Trying these line
screens generally gives you a more precise idea of the optimum
output for a particular image.

Scanner Resolutions

Another way to insure high quality output for your images is to
determine the optimum scanning resolution.
7-4 Advanced Imagingbb
LPI
75
50
38
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