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3-4 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
color, while “diffused” highlights contain a min-
imum amount of color. All densities less than
the diffused highlight slope to white at a 45º
angle. When setting Highlight and Shadow
points, PowerColor uses the values within the
Diffused Highlight and Shadow area of the Tone
and Cast window.
Setting the Input Range automatically with Auto Range
In the Control bar 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 RGB values shown in the Diffused Highlight and Shadow
fields at the bottom of the Tone and Cast 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).