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todryan
18th November 2016 7:55

8 Calibration
The vDot4 plugin is supplied with a number of calibration curves for specific media and resolution.
These curves are created with reference printers of the same type that the plugin is intended to
support.
In many cases printers will have characteristics so similar to the reference printers that no additional
steps are needed to get good quality output. However, it can be helpful to calibrate your printer to
compensate for differences between it and the reference... 8 Calibration
The vDot4 plugin is supplied with a number of calibration curves for specific media and resolution.
These curves are created with reference printers of the same type that the plugin is intended to
support.
In many cases printers will have characteristics so similar to the reference printers that no additional
steps are needed to get good quality output. However, it can be helpful to calibrate your printer to
compensate for differences between it and the reference machine.
8.1 Tools and materials
The RIP includes facilities for interfacing an automatic strip reading measurement instrument such as
the X-Rite DTP-41. However, for occasional calibration you can also use any quality instrument capable
of reading color densities in Status T format.
Note: The DTP-41 is not only able to measure color densities required for calibration, but it is also a
spectrophotometer which is a required to create ICC profiles.
You will require a good supply of media. Note that the RIP can only be calibrated for media listed in
Appendix A, “Inks and media”—for which Global Graphics provides internal calibration targets. To
create an initial calibration curve for other media types requires the use of additional tools not provided
with the vDot4 plugin.
8.2 Printing a target
This step is essential and cannot be omitted.
Start by ensuring that you have created a Page setup with the correct settings for the calibration targets.
The Color drop-down menu box will display vDot4 and Calibration should show None. This
example describes how to calibrate an Epson 7890 using Epson Standard Proofing Paper at 720 dpi. A
suitable Page setup called 7890 Color vDot is created for this purpose.
1. Select Output > Print Calibration. The following dialog ia displayed.
Figure 12 Print Calibration
OKI PCL PLUGIN
CONTENTS 14
CONTENTS 14
2. Highlight the correct Page setup, and click Print uncalibrated target. The RIP will generate a special
four-color target which you should print on the correct media type.
8.3 Measuring the target
Once the target is printed it must be measured.
8.3.1 Using Genlin
If you do not have a strip-reading densitometer such as the DTP-41 supported by Genlin, and you
wish to use a manual Status T densitometer, skip this section and go to “Entering measurement data”
on page 15.
1. If you have the DTP-41 or similar instrument, use the Genlin application installed with your RIP.
Locate the Genlin application (genlintool.exe) inside the RIP folder and launch it.
2. Select File > Configure from the menu bar. To display the following dialog:
Figure 13 Genlin Configuration dialog
3. Use the Change button to locate the RIP you are calibrating. Highlight the SW folder within the
RIP folder before clicking OK.
4. Use the Instrument drop-down to select the correct model of your measuring device.
5. Set Measure to Status T,
6. Set Media to Press Paper.
7. Set the Port to the serial port to which you’ve connected the measurement device.
8. Click OK to close the configuration dialog.
9. Select File > Read Target. A box with one or more Reference Numbers is displayed. Each time the
RIP generates a calibration target it records the details in a database and gives each target a Reference
Number. This number is printed on the target. Check the target printed in “Printing a target”
on page 13. Note the Reference Number and highlight the correct number in the list. Then
click OK.
10. Verify in the next screen that Genlin is expecting to read the correct number of colors for this target,
and click Read. For each color strip, Genlin displays a confirmation prompt.
11. Arrange the target in the direction of the arrow with the first (Cyan) strip under the measuring
head and slide the target under the head until it stops. Click OK and feed the target gently
through the reader.
12. Repeat this process for each of the four colors, after which Genlin will display a message indicating
that the RIP may now import the linearization data. Click OK.
13. Genlin has placed a file of measurement data in the RIP folder ready for the RIP to import.
OKI PCL PLUGIN
CONTENTS 15
CONTENTS 15
8.3.2 Entering measurement data
1. From the Harlequin RIP select Output > Calibration Manager. The following dialog appears:
Figure 14 Calibration Manager
2. In the Device drop-down menu, select the device that you are calibrating. This must be the same
device name as was selected in Page setup when you printed the Calibration Target.
3. Click New. The following dialog appears:
Figure 15 Edit calibrated target dialog
Profile
Use this drop-down to select the same Calibration profile that you chose
in Page setup, which must match the media. This underlying Calibration
profile provides the target information (aim curve) against which
you will calibrate the printer.
Name
Enter a convenient name for this calibration set.
OKI PCL PLUGIN
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Resolution
Calibration is only accurate at one resolution, so select the same resolution
as selected in Page setup. A warning is displayed in the RIP monitor,
should you attempt to use it at a different resolution.
8.3.3 Entering measurement data—manual
If you are using a hand-held densitometer make sure it is set to the Status T response curve.
Measure the density values for each Cyan patch on the target and enter these values in the boxes.
When you have finished entering the Cyan data, select another color in the Channel drop-down, and
repeat until all four sets of values have been entered. When completed click OK.
8.3.4 Import data from strip reader
If you used Genlin to create an import data file as described in “Using Genlin” on page 14, and click
the Import button.
The Import Measurements dialog box shows a list of the four color channels contained in the import
data file. Click Import.
The RIP will immediately import all the data values and change the numbers in all the boxes for all
four colors. Click OK to save the Calibration set.
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- todryan giúp dc khúc nào hay khúc đó cũng dc ạ, toàn từ chuyên ngành mà mình thì ngu đặc phần này
  0 · 18th November 2016 8:02
- Darkangel201 Chỉ muốn tặng bạn 1 câu thôi: "If you are good at something, never do it for free"
  2 · 18th November 2016 8:10