Scan Quality
Copyright © 2008 BERTL Inc.
September 4, 2008
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Page 17
August 2008
Contex SD4400
www.bertl.com
SCANNER ACCURACY
BERTL analysts performed a series of quality tests on the
scanners. We used our Applied Image (QA-1) test chart
for evaluating the scanner’s horizontal and vertical
accuracy. Instead of measuring the accuracy between two
end points, we instead only measured a random selection
of 6” width. Our test results indicated that:
SD4400 Series
Accuracy %
Horizontal
0.15
Vertical
0.03
The vertical result is excellent and is well below the
vendor’s claimed accuracy of 0.1%. The horizontal of
0.15% is clearly below the 0.1% specification but never
the less fully acceptable.
The SD4400 series scanner supports adjustment of
vertical precision. You do that by typing in a known
distance and then adjusting it for precision.
TEXT SHARPNESS
Text sharpness is another test where we look at the
impact of scanning small text size at low, medium, and
high resolutions. As the results to the right show, the SD
series with its 1,200 dpi optical resolution, has no problem
scanning small text characters at low resolutions.
Small text scanned at 200 dpi
.
Small text scanned at 400 dpi.
Small text scanned at 600 dpi.
The test result is one of the best we have seen lately, and
we contribute this fact to the much higher optical
resolution of the SD series compared to other scanners in
the industry.
WHAT WE LIKED
•
BERTL liked the scanner’s vertical accuracy, which
we attributed to the higher geometrical accuracy of
CIS technology-based scanners.
WHAT WE WOULD LIKE TO SEE
•
We have not recommendation at this time.