Apogee Photo Magazine

Adjusting Your Nikon Scanner Software for Optimum Results,
Part 2
(Part 1)

by  Michael  Goldstein

 

(Editor's note: Although this article deals specifically with the Nikon Coolscan, the controls and techniques are virtually the same for all scanners of this type, and should be transferable to any scanner.)

 CURVES  (The following discussion assumes an RGB color space.)

• The CURVES TOOL, in the TOOLS PALETTE, may be used just like the color correction /contrast range tools (IMAGE - ADJUST - CURVES/LEVELS) in Adobe Photoshop and other imaging programs. This tool is a combination of the LEVELS and CURVES tool that serious Photoshop users employ. (See my article on Color Correction in Apogee Photo Magazine).

• The histogram (the black bumpy area in the CURVES graph) represents the actual pixels in the image to be scanned. The horizontal axis of the graph represents the distribution of the pixels over the total contrast range of the scan, over a scale of 0-255. If the black point slider (left-hand slider) or the white point slider (right-hand slider) points, on the axis, beyond the available pixels, then contrast range will be wasted.

 

        Slide the appropriate slider over, until it is exactly under the end pixels in the histogram. After moving one or both sliders, restore the middle slider (mid-tone adjustment) to the exact middle of the graph axis. 

 

•   The vertical axis of the CURVES graph represents the output black-white contrast range of the scan over a scale of 0 - 255 and shows the relative distribution of the image pixels. Most printers cannot reproduce this complete range. If we reduce this contrast range (change the black point and the white point) to 10 and 245 (printing industry standard figures of merit), we’ll make maximum use of printer capability.

1)      In the bottom left window, “click a cursor” and change the black point setting from 0 to 10 (or move the bottom left slider). 

2)      In the top left window, “click a cursor”, and change the white point setting from 255 to 245.

     (You’ll see the RGB—black--curve change in the appropriate fashion.)

 

Initial scans often seem to have a slight blue colorcast.

 

1)      In the CHANNEL window of the CURVES dialogue box, change from RGB to BLUE, so you can make changes to only the color blue in the image.

2)      Move the blue curve down (reducing the blue color in the RGB image) using “drag and drop” until the input reads 133 and the output reads 113. (These are starting points.)

3)      Change the RED curve from 133 to 118. Change the green curve from 133 to 111.

4)      Reset the CHANNELS window to RGB.               

5)      On the RGB curve, pull up the curve (increase brightness) from 103 - 149. Put contrast locks on this curve, so that 69 becomes 91, and 150 becomes 195. This will increase contrast and color saturation.

6)      You can “click off” the curves tool to see the effect on your scan preview.

7)      You can save these CURVES settings as your defaults, independent of other defaults, so you can return to factory settings at any time for just the CURVES settings. Click on the diode symbol, upper right-hand side, for the CURVES SETTINGS menu.

 

7.      DIGITAL ICE CUBED

                 The DIGITAL ICE^TM utility (Image Correction and Enhancement) that is included with the Nikon software is invaluable for ensuring minimum “cleanup” of the resulting scanned images. Although it increases your scanning time slightly, it’s well worth the delay, and I leave it turned on (NORMAL) as a default setting.

        

         Tool Palette - Digital Ice Cubed

1)     Enable Digital ICE.

2)    On the main software window, DIGITAL ICE should now be shown as “NORMAL.”

 

8.      OTHER ENHANCEMENTS

                 There are two other enhancement utilities that you should plan to use if you’re going to print the final scan. These are Digital ROC (Restoration of Color) and Digital GEM (Grain Equalization and Management). Use of these will greatly increase your scan times but deliver much better scans. For example, use of Digital GEM will eliminate grainy sky areas that sometimes result from enthusiastic UNSHARP MASKING.

 

To use these, enable the POST PROCESSING option, found directly under the control for Digital ICE. Set the Digital ROC slider for a value of 5, and the Digital GEM slider for a value of 3. You will see these adjustments reflected in the main program window, just about the PREVIEW and SCAN buttons.

 

9.      SCANNER EXTRAS

1)      Disable “Autofocus when film inserted.” If you autofocus before your preview, this is redundant.

 

2)      Accept the 8-bit default for the BIT DEPTH adjustment. This is the equivalent of 24-bit depth for RGB images. Anything greater increases file size and can’t be detected by the eye.

 

10.    UNSHARP MASK

        The “Unsharp Mask” (the origin of the name is lost in the prehistory of the printing industry) is actually a utility for sharpening the resultant scan. It works in a manner similar to the UNSHARP MASK in Photoshop. Scanning an image tends to result in a scan that’s softer than you might prefer, so sharpening before the scan is a good idea.

        Through experimentation, I established my default UNSHARP MASK settings as:

     INTENSITY ------- 15%

     HALO WIDTH----  15%

     THRESHOLD-----   3 levels

 

           Once you’ve established the initial settings for your software, you can save them in a file, and they’ll become your default settings upon initialization. Remember that your “saved file” format specification won’t change with different sets of default settings.  You must change the preferred file format manually in the PREFS section.

 

           Your filename will appear in the SETTINGS menu, on the main software display. You can return to the original settings at any time by using SETTINGS - RESET TO FACTORY DEFAULTS.     

                           

11.    SETTINGS - SAVE SETTINGS

        Choose a filename, such as “Mike’s Defaults”. This filename (and others you might add) will appear at the bottom of the SETTINGS menu. My collection includes “TIFF Defaults” and  “JPEG Defaults.” You can delete unwanted sets of default settings later, using the SETTINGS menu.