Optional Step (Polaroid 4000 and MicroTek
Choose the Special tab in the Defaults
window, the dialog shown below
using either the Polaroid SS4000 or MicroTek 4000T I recommend that the checkbox adjacent to Limit
Gamma Slope is unchecked. This is a change from my previous
recommendation and results from a detailed analysis of the impact this
feature has on scanned images. When Limit
Gamma Slope is activated it has the effect of compressing the
shadow tones so as to minimise dark area noise in very dark images.
Whilst this feature is quite useful for situations were the IT-8 module
is not available it can cause considerable loss of shadow detail when
calibration has been applied. It can also cause severe posterisation in
Depending upon your scanner type LaserSoft supplies either a Reflective or
Transparent type target. Additional IT 8 targets can be obtained
LaserSoft These target will be labelled LaserSoft Imaging
and should contain a reference or Charge number. Newer
targets will contain a
Barcode somewhere along
the bottom edge. The example scan shown below uses a LaserSoft
reflective type IT8 print. Other than the barcode you should
find that the appearance of IT8's from other vendors is broadly similar. If calibrating a scanner in
SilverFast Ai place/insert the IT-8 calibration print/slide onto/into the scanner.
SilverFast HDR requires that the image be pre-scanned in SilverFast Ai
or another third party scanning application.
We begin by pressing the Prescan button.
A Prescan image of the IT-8 target should now appear on-screen. Make
sure that it appears in the Landscape format. If it doesn't you
should rotate or flip the image as required. Failure to have the IT-8
target in the landscape format may result in an error message.
From the menu strip shown on the left-hand side of the
Preview window, Press the Calibration button
Cropping of Prescan IT-8 Target
The prescan image MUST now be cropped as indicated by the red
boundary in the screenshot shown above. Each corner of the cropping
marquee is independently adjustable so a slight skewed or rotated scan
can easily be cropped so that all of the coloured/neutral patches are
fully covered. From here on the process of calibration is relatively
If the following warning appears to advise you that the Internal RGB
Profile is missing; don't panic as it's really telling you that the
steps taken in Figure 3 needs to be reversed once the
calibration process is completed. Click OK and proceed.
Next the main IT-8 Calibration dialog will appear. This dialog is pretty
much self-explanatory with step-by-step instructions appearing at each
stage throughout the process.
Remember that it's important that you frame/crop the relevant area of the image as
shown (i.e. landscape format). SilverFast displays shows a grid over the
prescanned image so you should be able to quickly confirm that your
cropping is accurate.
Press the Start
button and the scanner begins the greyscale balance, once this is
complete SilverFast will check the scanned image for the presence of a
LaserSoft compatible barcode. If the barcode is found SilverFast will search your hard drive or the LaserSoft web
site for the appropriate reference data file. If the file is found
SilverFast automatically proceeds to adjust for the
colour balance and that's it. If the reference file can't be found (usually
because the IT8 target was not supplied by LaserSoft) the following
warning appears. You'll need to select the correct reference data file
manually before continuing.
Once completed SilverFast will inform you that the process of
calibrating the scanner has been successful and you'll be asked to save
the ICC profile. Make sure that you give the profile a name that is
To complete the calibration process simply choose OK
from the IT-8 Calibration dialog. If the calibration has been successful and the profile created is
available for use. You should now see that the calibration button
has changed to become more coloured than before; i.e. it will look like
The final step of setting up the SilverFast IT-8 colour management
system takes us back to CMS dialog of the Defaults window.