Oce Arizona 250 GT User Manual page 120

How to Determine Media Advance Correction
before you start the correction procedure. One tell-tale indicator of telescoping and
significantly varying tension is to look at the Media Advance Correction Print near
the sides; if under stepping banding occurs on one side, and overstepping on the
other, the banding is not the result of an incorrect correction factor, rather it is
possibly due to an improper media load.
How You Determine the MACF
In the 'Roll Media Manager' menu you can select the 'Media Advance Correction
Factor' (MACF) and enter a value from 0 to 100. A value of 50 signifies that the
thickness of the media remains the same, a value larger than 50 signifies the
thickness of the media is reduced over the capstan, while a value smaller than 50
signifies the media acts as if it is thicker over the capstan.
To arrive at the MACF for a given media, a Special Print is used. The print images a
series of colors that are most susceptible to Understepping and Overstepping; these
colors are used to identify a range where no under or over step banding occurs.
Depending on the given media, some of the colors may be more susceptible than
others to this banding (this is why more than one color is present on the test print).
The test print used for the calibration of the MACF can be found in the Special Prints
module. It is called the Media Advance Correction Factor print.
Procedure to Determine the MACF for Overstep (White gaps)
Click the Roll Media icon to bring up the Roll Media Manager.
1.
Enter a large value for the media advance correction factor, (say 75) and print the
2.
image. Verify that white gaps are present (spaced a swath width apart); if they aren't,
enter a larger value and reprint (continue until the white gaps are noticeable).
Once gaps are verified, reduce the correction factor value by 10 or 5 and reprint.
3.
Continue reducing the value and reprinting the test image until white gaps are no
longer visible. At this point fine-tuning can be done if desired, changing the
correction factor by values of around 2 or 3 to determine the exact spot banding
occurs; this level of accuracy usually isn't necessary. Record this value as the high
end of your MACF range.
Procedure to Determine the MACF for Understep (Dark lines)
Enter a low media correction value (say 15), and verify that noticeable understepping
1.
occurs, in the form of dark lines spaced a swath width apart.
Once understepping swaths have been verified, increase the media correction value
2.
by 10 or 5, stopping when you no longer see dark lines (Again, finding the exact
value where banding occurs can be performed, though it is usually not necessary).
This is the low end of your MACF range.
120 Chapter 6 How to Operate the Roll Media Option