Xante Accel-a-Writer 8300 Reference manual

____________________________________ Advanced Features 8-1
Chapter 8-Advanced Features
Chapter Overview
Introduction.....................................................................................8-3
Levels of Gray.................................................................................8-3
Line Screens....................................................................................8-4
Scanner Resolutions........................................................................8-4
Line Art Scanning.....................................................................8-4
Halftone Scanning ....................................................................8-5
TIFF, PICT, EPS Formats.........................................................8-5
Gamma Corrections ........................................................................8-6
Negative Enhanced Imaging Technology........................................8-8
Enhanced Screening........................................................................8-8
RAM Enhance.................................................................................8-9
Font Accelerator and RAM Disk ..................................................8-10
Accurate Calibration Technology .................................................8-11

8-2 Advanced Features ____________________________________
Notes

____________________________________ Advanced Features 8-3
Introduction
To take full advantage of your printer’s high resolution and make
your images look their best, it is important that you understand levels
of gray, line screens, scanner resolutions, scanned image formats,
and their uses within specific applications.
This chapter explains these concepts and describes how to use them
with XANTÉ’s Enhanced Screening Technology, NEIT, XANTÉ’s
Halftone Calibration Technology, to achieve the best quality in
output.
Levels of Gray
A laser printer’s resolution is measured in dots per inch (dpi). The
standard resolution on your printer is 600 x 600 dpi, which you may
have upgraded to 1200 x 1200 dpi.
The human eye can detect approximately 256 shades of gray. The
more levels of gray (number of shades) produced in a halftone
image, the smoother the image appears.
The following simple formula can help you determine the shades of
gray used to produce an image:
dots per inch
lines per inch
For example, if you print at 600 x 600 dpi with a 60 line screen, the
image produced has 101 levels of gray (600/60 = 10; 10 x 10 + 1 =
101). For more levels of gray at 600 dpi, the line screen or lines per
inch (lpi) has to be reduced.
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.
()
2
+1

8-4 Advanced Features ____________________________________
Use the following table as a guide to produce 256 levels of gray.
LPI To Achieve 256 Levels of Gray
Printer
Resolution LPI
1200 x 1200 dpi 75
600 x 600 dpi 38
Line Screens
The number of levels of gray you would like to achieve is one factor
in determining the appropriate line screen to use. You do not always
have to achieve 256 levels of gray for the best output. Some
experimentation usually is necessary to produce the best possible
output.
We found that line screens (lpi) of 85 for 600 dpi and 85 - 106 for
1200 dpi work well for most images. Try these line screen settings or
choose the number of gray levels to produce using XANTÉ’s
Enhanced Screening Technology (see “Enhanced Screening” later in
this chapter).
Scanner Resolutions
Another way to insure high quality output for your images is to
determine the optimum scanning resolution.
Line Art Scanning
For line art, the optimum scanning resolution would be at the same
resolution as the output device, especially when reproduced at the
same size. For example, when printing from your printer in the 600
dpi mode, the scanner resolution should be set at 600 dpi.

____________________________________ Advanced Features 8-5
Halftone Scanning
The halftone scanning resolution is usually lower than that of the
output resolution. Black and white images generally should be
scanned at a resolution of 2 times that of the line screen used, if
printing at 100% size. Use the following formula to determine the
optimum resolution.
desired lpi x 2 x % of original size
For example, if a line screen of 95 is used, the scanner resolution
should be set to 190 dpi (95 x 2). If that resolution cannot be
selected, choose the next higher resolution available. If the previous
example were to be printed at 75% of original size, then the scanner
resolution should be set to 142 dpi (95 x 2 x .75).
Scanning the image at a lower than optimum resolution results in less
detail. Scanning at a higher resolution increases the file size and the
processing time, and it may only slightly increase the amount of
detail.
TIFF, PICT, EPS Formats
After creating or scanning the image, you need to decide the format
in which to save it. The three most common formats are TIFF
(Tagged Image File Format), PICT (from Picture), and EPS
(Encapsulated PostScript) files. If you use a scanning application
such as Photoshop, make sure to choose the appropriate line screen
under Page Setup before saving the image. This is essential for
importing the image into other applications. Some programs do not
allow you to change the line screen of an individual PICT or EPS
image once it is imported.
PageMaker only allows you to change the line screen of a TIFF file by
clicking the image and choosing Image Control under the Elements
menu. For version specific information, see your PageMaker
documentation.

8-6 Advanced Features ____________________________________
QuarkXPress only allows you to change the line screen of an
individual TIFF file through the Style menu. For version specific
information, see the QuarkXPress documentation.
For additional application information, see appendix B, “Application
Notes and Page Design.”
Gamma Corrections
XANTÉ Halftone Calibration Technology includes a sophisticated
gamma corrections feature. This feature allows you to adjust printer
output for ink, media, file, and environmental conditions. For example,
if a scanned image is too dark, you can select a new gamma setting to
lighten and enhance the details. Gamma corrections bring out details
that can be lost when printing at higher line screens or when dark photos
are scanned.
Your printer offers seven standard gamma correction curves, 0 (no
change) through 6 with 3 as the default. Settings 0 through 5
progressively lighten the midrange values. Gamma 6 allows you to
create a negative (reverse) image, (required by some printing
processes) without using a software application. Figure 8.1 illustrates
the effects of the standard gamma correction settings.
You also can create and download up to seven custom gamma curves
to calibrate your printer for specific conditions. Custom Gamma
Curve 0 can be selected as the printer’s default gamma correction
curve using the Linear option of the front panel Gamma menu. See
“The Gamma Menu” in chapter 5, “Gamma” in chapter 6, and
“Calibration with a Densitometer” in chapter 3 (Macintosh) or
chapter 4 (PC).
All fourteen gamma correction curves can be selected on a per job
basis through the printer features section of the PPD. The PPD
setting overrides the front panel setting for the specific job.
If you use gamma corrections in combination with XANTÉ’s new
enhanced screening technology, you can further fine tune your
output quality. See “Levels of Gray” earlier in this chapter and
“Enhanced Screening,” later in this chapter.

____________________________________ Advanced Features 8-7
1
10
Output Levels
Black White
Input Levels
Gamma 6
Black White
1
10
Output Levels
Black White
Input Levels
Gamma 5
Black White
1
10
Output Levels
Black White
Input Levels
Gamma 4
Black White
1
10
Output Levels
Black White
Input Levels
Gamma 3
Black White
1
10
Output Levels
Black White
Input Levels
Gamma 2
Black White
1
10
Output Levels
Black White
Input Levels
Gamma 1
Black White
1
10
Output Levels
Gamma 0
Black White
Input Levels
Black White
Fig. 8.1 Gamma Corrections 0 through 6

8-8 Advanced Features ____________________________________
Negative Enhanced ImagingTechnology
Traditionally laser printers were designed to print positive images.
XANTÉ’s innovative, patent pending Negative Enhanced Imaging
Technology (NEIT) is the first technology to address the problems
typically associated with producing negative images on a laser printer.
The patent pending technology can be purchased as an option for your
printer.
Previously, when a negative print was done on a laser printer, gray
scales were distorted and small spaces in text and lines were
obscured by toner bleed. NEIT addresses these problems, allowing
you to adjust the application of toner when producing a negative
image to produce crisp, clean lines and text. The image on the right
in figure 8.2 illustrates how NEIT can improve a negative print.
Fig. 8.2 The NEIT Difference
XANTÉ’s optional NEIT feature is controlled through the
MISCELLANEOUS:NEIT menu on the printer’s front panel. NEIT
menu settings are activated only when you select True in the
Negative Print option of the PPD. The options are 0 to 20; increasing
the number decreases the amount of plugging (filling in) of tiny
white spaces in text and hairlines on negative images. See “The
NEIT Menu” in chapter 5 and “Negative Print” in chapter 6.
Note: NEIT requires full frame buffering. See “Printer Memory
Requirements” in chapter 9.

____________________________________ Advanced Features 8-9
Enhanced Screening
XANTÉ’s Enhanced Screening Technology increases the number of
gray levels available for a line screen setting. The option can be set
from the printer’s front panel or through the PPD.
If you use the PPD, you can select the levels of gray and gamma
settings simultaneously. Gray level and line screen combinations of
enhanced screens are defined as:
Levels Line Screens
of Gray 600 dpi 1200 dpi
145 70 140
197 60 120
256 53 106
Font Accelerator and RAM Disk
Font Accelerator uses a percentage of available RAM disk to store
fonts for quick system access. Font Accelerator automatically loads
the most recently used fonts from the printer’s optional hard disk into
the RAM disk. This eliminates time usually required to access fonts
from the hard disk.
The feature can be enabled only on systems with 12 MB or more of
RAM, an optional hard disk, and with RAM disk set to at least 1
MB. See the “Font Accelerator Menu” and “The RAM Disk Menu”
in chapter 5. The printer must be restarted before Font Accelerator
becomes active.
Once Font Accelerator is active, it automatically updates the RAM
disk at runtime with the most recently used fonts. This update occurs
when the printer is in a READY/IDLE state. The front panel window
displays READY/FONT ACCEL during the update.

8-10 Advanced Features ____________________________________
The maximum amount of RAM disk available is equal to the total
RAM installed minus the amount of RAM required for standard
printer operation (a minimum of 8 MB). For example, a printer with
64 MB of RAM has 56 MB (64 - 8 = 56) available. RAM disk can be
enabled in 1 MB increments up to the maximum available amount. The
printer's default is 0, which disables RAM disk.
Note: When RAM disk is set high, the initialization process can be
extended at start-up.
Accurate Calibration Technology
X•ACT (XANTÉ’s patent pending Accurate Calibration Technology)
allows you to calibrate the printer to print more precise horizontal and
vertical lines.
Because of manufacturing variations and usage, a printer may not
print lines with the exact dimensions specified by the application.
X•ACT allows you to calibrate your printer to compensates for these
differences.
Your printer is calibrated before it is shipped, but it may drift out of
alignment over time. After using X•ACT to calibrate the line lengths,
adjust the alignment of the imageable area on the page using
Command Center. See “Procedures” in chapter 3 (Macintosh) or
chapter 4 (PC) for details on using X•ACT and your printer’s margin
alignment functions.
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