Nikon LS-3500 - LS-3510 - Manual (Page 45)

Using The Macintosh Scanner Plugin 5-13
Software Reference for Scanners
The same rules apply to Exposure . Changing the exposure values here will
affect Red, Green and Blue settings by an equal amount. This is a simple way to
increase the brightness of a dark original transparency, without affecting the color
balance of the resulting image. Again, the useful range of values typically falls
between 40 and 120.
The Black Level ranges from -15 to +15. This setting determines the
clamping level of the CCD for the maximum black in the image. Usually, the
D
max (or darkest black) of an Ektachrome transparency measures 3.0 on a
densitometer. The D
min
(the lightest portion or specular highlight) often measures
.8, making the overall range 2.4. This density range of dark to light is very typical,
but much higher than what we usually print on paper. The
Black Level Threshold
control permits the user to lighten or darken the blackest black in the image. This
means that as we lower the setting (when scanning positive film), the blacks will
get lighter and as we raise the setting, they get darker. This happens without
affecting the highlights or midtones of the image.
Auto Exposure/Auto Mode
Fig. 42 Auto Exposure / Auto Mode
The autoexposure icon (the icon on the left) will cause the scanner to do
what's referred to as a Prescan. That is, the scanner adjusts itself to the image by
determining density and contrast. It optimizes it's internal analog levels to make
the best scan possible. In most cases, the autoexposure will do such a good job
that you won't need to adjust the analog or digital controls.
The Auto Mode checkbox means that the plugin will ensure that the scanner
has made at least one autoexposure and autofocus before a preview or scan is
attempted. This will be reset if the film type is changed, or if Photoshop is quit,
then re-launched.
One of the really important features of the LS-3510AF is it's focusing and
auto-focusing features. This eliminates the need for different thickness slide
holders, as used by the LS-3500. In almost all cases, the standard autofocus (the
icon on the right) will assure you the sharpest image possible.
In some cases, however, such as with blurry images, or warped film, you may
wish to manually focus on an area of the slide. This is easily accomplished by
pressing the Manual Focus button. Pressing this button puts the plugin into a
manual focus mode. If you move the mouse over the preview area, you will see
that it becomes a magnifying glass with crosshairs in the center. Place this cursor
over the area you wish to focus on, and click the mouse button.
The scanner will take a small high-resolution grayscale scan and display it in
the preview area. You may then adjust the focus by using the slider (which has