UMAX Technologies PowerColor, User Manual, Page: 72 / 127

4-6 PowerColor User Guide
Setting Highlight and Shadow
The most important aspect of setting up a scan is defining where to place the
highlight and shadow point. PowerColor has an automatic as well as a manual
means for accomplishing this task.
Note: There are two types of highlights:
“Specular” highlights are areas that contain no
dot percentage of any ink, while “diffused”
highlights contain a minimum dot percentage.
All densities less than the diffused highlight
slope to a 0% dot at a 45º angle. When setting
Highlight and Shadow points, PowerColor uses
the values within the Diffused Highlight and
Shadow area of the Production Controls
Window.
Setting the Input Range automatically with Auto Range
In the Production Controls Window you will find the Auto Range Icon ( ).
By selecting this tool, an Auto Range will be performed on the active region. The
Highlight and Shadow point will be set to the values shown in the Diffused
Highlight and Shadow fields within the Productions Control Window. Also, these
points will be marked in your image by sticky densitometers.
How Auto Range determines Highlight and Shadow points
After the software has evaluated the image data it will make a series of decisions
as to where it will set the Highlight and Shadow point.
• Auto Range looks only at the densities of the image data that falls within the
current Region Crop. This is important to know because if you leave film
edge or an area beyond the image edge in your crop, the software will
include that data in its decision.
• The Highlight and Shadow points will not be set at the extreme minimum
and maximum, but at a percentage inside of the min and max. The reason
for this is to avoid setting the points on dust or scratches on the film.
• Due to the use of a catch light, data is never clipped, regardless of where the
highlight and shadow is set. (We will explain this later on with a discussion
of the Diffused Highlight.)
• PowerColor searches for densities that are closest to neutral (equal).