Avision IS1000 (BF-1008S) - Manual (Page 103)

User’s Manual
8. Troubleshooting
8.1 Questions and Answers
Question: Why is it that the scanned image always
comes out to be too dark?
Answer: 1) Modify the Gamma setting to1.8~2.2 for your
monitor and, when printing, set the Gamma
setting to 2.2 for your printer.
2) Adjust the Brightness setting from the TWAIN
user interface to get a brighter image.
Question: The scanner works well except for the line art
image. The lines in the image seem to be
much thicker than the original one.
Answer: Increase the Brightness or adjust the Threshold
setting to improve line art image.