User manual

8 • Scanning color negatives

ColorQuartet 5.0 Pro

Advanced features in the “Negative Profile” window

If you find that an image is difficult to adjust with the procedure described under “Previewing

and scanning negatives,” the Negative Proﬁle window includes some additional tools you can

use.

The Histogram and its relation to the Reversal Curves

• The Histogram (bar graph) shows the distribution of tones in the preview-scanned negative.

These tones can be thought of as the “input” values in the reproduction process.

• The Reversal Curves are digitally applied to these tones, resulting in the “output” values, i.e., the

reproduced image.

• The X axis (bottom scale) of the Histogram and the X axis of the Reversal Curves are the same.

For any given value along this scale, trace a line straight up to the reversal curve and then

straight to the left to find the value on the Y axis (left-hand scale) that that tone value will be

given in the reproduction.

• When you click on a point in the feedback window, its input and output values are indicated

by small colored triangles at the bottom and left-hand scales of the Reversal Curves grid. When

you adjust gray balance as explained under “

Previewing and scanning negatives,” your goal is

to take the existing, different values for red, green and blue and set them all to the same value

in the reproduction. This is graphically represented by the three small triangles on the left-

hand scale moving to a position on top of each other.

Working with the Histogram

• Separate histograms are displayed for the red, green and blue channels of the image.

• To work with a histogram, foreground it by clicking on it or on the red, green or blue stripe to

the right of the histograms.

• The left-hand edge of the histogram represents the fully exposed (dark) part of the negative,

which will become the highlight in the positive reproduction.

• The right-hand edge represents the unexposed (light) part of the negative, which will become

the shadow in the reproduction.

• When a negative is scanned, dust and dirt appear as dark spots that may give a false highlight

in the positive reproduction. Scratches appear as light spots that may give a false shadow. A

long, low “tail” at the end of a histogram indicates that the original is dusty/dirty (left-hand

end) or scratched (right-hand end).