[sane-devel] problem with Nikon Coolscan II

Henning Meier-Geinitz henning@meier-geinitz.de
Wed, 26 Nov 2003 12:00:04 +0100


On Tue, Nov 25, 2003 at 12:03:25PM +0000, Richard Poole wrote:
> I have a Coolscan II connected to an Advansys ABP940U SCSI card. I
> haven't owned this scanner from new and I've never seen it working
> correctly. So I've no idea what's the source of the following weird
> problem.

Make sure that it's not some sort of SCSI problem, e.g. by testing
with a different SCSI controller.

Also check that the scanner works in pronciple, e.g. by testing it
with Windows.

Which scanner is it exactly? Our page only lists the names like that:
"LS-20". If it's none of the scanners listed there, it's probably just
not supported yet. The manpage "sane-coolscan2" shows the names for
Coolscan III and IV, but not for II.

> When I scan, using the coolscan backend, some lines of the scan are
> offset by 1 pixel from the previous line; about 60% of lines, seemingly
> at random, are affected, so after 24 lines I'm typically 14 or 15 pixels
> across. After 62208 bytes (24 lines of grayscale or 8 of color), the
> next line is back at the original position (62208 bytes is the amount of
> information returned by the scanner from a single SCSI read). This
> produces a jagged effect; http://guests.deus.net/~rp/sample.png shows the
> top corner of a scan, showing the effect I've described at the edge
> between a slide mount and a very light slide on a grayscale scan.

Strange. Looks like the backend isn't counting correctly. However, I
don't remember any other report of that behaviour until now. But I
haven't searched the archive.

> So my questions are:
> - is this scanner functioning properly but being driven wrongly,
> malfunctioning but usable, or a paperweight?

Well, our list says the status is "basic" for all scanners of the
coolscan backend. So it should work if it's one of those. However, the
coolscan backend hasn't been maintained since a very long time.

> - if the scanner is OK, what is my best route to getting proper scans
> from it? I'm happy to do some C programming, so I'd need to know what's
> the best way to get specs and whether I should be working on the
> coolscan or coolscan2 backends.

You could try asking Nikon. Or try to "listen" to SCSI commands sent
to the scanner by the Windows driver. See our "contributing" page.

You could also try to contact the deveopers of the coolscan and
coolscan2 backends. Their names and addreses are in the file AUTHORS
that comes with sane-backends.