[sane-devel] Epson 1250u vs plustek-45-TEST5

Jaeger, Gerhard gerhard@gjaeger.de
Tue, 7 Jan 2003 18:56:29 +0100

On Monday, 6. January 2003 20:37, Gene Heskett wrote:
> Post a notice here when it is please :-)


> >> I don't think this is quite "Ready for prime time" :-(  We still
> >> have that white vertical line artifact, and the segfault at the
> >> end of the scan seems to be somewhat of a coin toss.  Phase of
> >> the moon, odd/even minute, whatever.
> >
> >- phase of the moon! I didn't get any segfaults here after a scan.
> Now wait a minute, I don't want any MORE poltergeists in my system!
> With kwin crashing if I'm playing a game and actually win, I don't
> need any more ghosts.  I've also downloaded the latest bugzilla,
> and installed 20 megs worth of stuff from CPAN that it says it
> needs, but I still can't file a bugreport against kwin and there
> does not appear to be any humans at bugs.kde.org to override
> things.
> Thats O.T. here, so back to sane/plustek:
> Whats the appropriate debugging line I should use to turn it on &
> see if it can be trapped/pinpointed?
> >> Suggestion/feature request:  Can this thing get a focus
> >> adjustment made available in the gui, and saved in the prefs?
> >> We no doubt have some users who aren't quite comfortable
> >> shuffling around in the source code with vi just to get the
> >> proper focus/registration for their individual scanner, and
> >> obviously from this, hard coding it isn't going to be optimum
> >> for everybody.  Mine was pretty bad when set for 16, but I
> >> remembered 8 was pretty good from previous testing, and it still
> >> is.
> >
> >No need to have this adjustment, as it should be okay for all
> >devices...
> How did it get reset to 16 then?  Possibly for the TPA maybe?  But
> that seems counterintuitive to me, or do positive numbers raise the
> scanhead, in which case getting into focus for a mounted slide,
> that setting may be correct.  Somehow I had it fixed in my mind
> that greater numbers meant farther from the glass, not closer.
> In any event, the TPA is surely going to need a different setting if
> for no other reason than the thickness of the slide mount frame
> raising the film off the glass at least far enough to get rid of
> the newtons rings.  Also in that event, the array isn't capable of
> holding a seperate value for each mode.  Fixing that will be a
> major hack too.  :(  Which is half the reason I asked for the prefs
> setting instead, which is probably about the same amount of coding
> & caffiene in the long run.

I think there's something wrong here;-) Sensordistance has nothing to
do with the focus... For the Plustek backend it is used in conjuction
with the optical resolution to determine the min available x resolution:
600dpi / 8 = 75dpi...
That's all here, for other backends it sometimes means the "distance"
between red, green and blue lines.