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Océ CS 5050/5070 User Manual
Scan resolution
Choosing the right resolution for the output print size (as well as the amount
of scaling needed after scanning) determines the best scan resolution for each
image. A resolution that is too low will diminish the print quality (insufficient
detail). A resolution that is too high slows down the raster image processor
(OGSL) without adding quality to the image.
Use the following guidelines to set end resolution:
■
150 dpi for sharp, detailed images intended for close viewing
■
100 dpi for viewing from a significant distance
■
Keep text and logos as vector information (i. e. Postscript fonts and formats),
which will always print at the printer’s resolution.
Most scanners can interpolate or “imitate” high-resolution scanning. However,
do not use the interpolated resolution of your scanner to compute the image
size. Instead, use the scanner’s highest true optical resolution to maintain
image quality.
Post-scanning image correction and sharpening
Before printing a scanned image, you must perform some basic image
corrections and sharpening to ensure a high-quality, wide-format colour print.
Tonal correction
If necessary, remove the colour cast from the midtones of an
image using a function such as “Auto" levels in PhotoShop. This function
allows you to re-adjust the black and white points in the image and redistribute
the intermediate colours proportionately. In most cases, this correction is
sufficient for properly exposed images. However, in very dark night scenes or
in very white snow backgrounds, you must make a manual correction by
adjusting the histogram.
Sharpening
To improve the edge details of an image, use the “Unsharp Mask
filter” in Photoshop. This can digitally refocus an image that has become
blurred from scanning or interpolation. A small over-estimation of the filter
effect can be diffused in the printing process; however, a large over-estimation
can give the image a hard, pixelated appearance.
Summary of Contents for CS 5070
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Page 107: ...107 Oc CS 5050 5070 User Manual Appendix A Glossary...
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Page 111: ...111 Oc CS 5050 5070 User Manual Appendix B Quick reference card...
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Page 123: ...123 Oc CS 5050 5070 User Manual Appendix D Technical specifications...
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Page 127: ...127 Oc CS 5050 5070 User Manual Appendix E Safety information...
Page 131: ...131 Oc CS 5050 5070 User Manual Appendix F Miscellaneous...