FOCUS ELEVATION
The
Focus Elevation
function manually moves the focus point towards or
away from the mounting plate. This function can be used to optically
defocus an image.
ACCESSING “AUTOFOCUS” AND “FOCUS ELEVATION”
The
Autofocus
and
Focus Elevation
functions are accessed by clicking on
the
Focus & Aperture
button in ColorQuartet’s
Preview Setup
window or by
opening the
Focus
section at the bottom of the
Scan Setup
window. For
each individual job, you can specify:
• Whether you want to use
Autofocus
.
• Whether you want to manually change the
Focus Elevation
, and by how much.
TIPS FOR USING “AUTOFOCUS” AND “FOCUS ELEVATION”
•
Transparencies only, emulsion side down:
If all the images on the mounting
plate are transparencies and all are mounted with the emulsion side towards
the scanner bed, the default focus found during focus calibration will be
sufficient to produce images with optimal sharpness.
•
Different types of originals in the same preview scan:
If you are scanning
some transparencies emulsion side up and others emulsion side down, or
if you are scanning reflection originals of varying thickness, use the
Auto-
focus
function to ensure optimum sharpness for each image.
•
Rescreening:
The best way to blur existing halftone dots in a printed
original is to use the digital
Descreen
feature in the
Focus
section of
ColorQuartet’s
Scan Setup
window. However, it is also possible to defocus
the optical system mechanically. To do this, move the focal point toward
the mounting plate by setting
Focus Elevation
to a value between 0 and –500.
The value necessary will depend on the original’s halftone screen. The
coarser the screen ruling, the bigger the dots, and the more the scanner
must be defocused. You may have to experiment a little to find the most
appropriate levels of defocusing for various screen rulings. Make a note of
Scanner calibration and focus adjustment
4•4
ScanMate F10 • Operator’s Manual
