Microtek 3840 scanner is not producing good images

I know that this is an ancient scanner, but it works quite well in Windows 7 (although it takes quite a bit of work manipulating driver setup, since it is not supposed to work under the new OS).

For whatever reasons, the scans that come up in Linux have areas that are too bright, as if solarized, and line weights are not consistent. I have adjusted several of the settings in both directions, but the problems do not seem to change much. If it did not make nice clean scans under Windows I would assume a hardware issue, but that does not seem to be the case.
(What is “Threshold” anyway, does anybody know?)

The hardware was properly identified by the computer, including model number, so clearly the software knows what it is.

Thanks for your help.

SANE supported scanners shows that the sm3840 backend supports this device. Any adjustement available will depend on what the backend provides, so adjustment may be limited. As such, I can only suggest reporting any issues to the SANE developers


(What is “Threshold” anyway, does anybody know?)

This may answer your question



defines the brightness level in % that is needed to get a white point in lineart (black/white)
mode. You have to enter some options in the enhancement setup and the backend needs to make available
a threshold option.