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Optional Step (Polaroid 4000 and MicroTek 4000T specific)

Choose the Special tab in the Defaults window, the dialog shown below should appear.

 

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When 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 the shadows.

Step 2 - Calibrating the Scanner

Depending upon your scanner type LaserSoft supplies either a Reflective or Transparent type target. Additional IT 8 targets can be obtained directly from 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.

 

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Prescan/Scan Buttons

 

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  X.

 

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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 straightforward.

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.

 

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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.

 

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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 easily recognised:

 

 

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  X.

The final step of setting up the SilverFast IT-8 colour management system takes us back to CMS dialog of the Defaults window.

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