vuescan IR misalignment on Epson 4870

[Torbjörn Einarsson]

Searched the archive and found that this type of problem was discussed in
the beginning of October, but anyway thought it might be good reporting
another occasion of the problem.

My problem is that VueScan (8.1.7 professional) produces IR scans which are
roughly 16 pixels (at 2400 dpi) displaced regards to the RGB components
(along the short direction of the scanner).
It does not happen always, but often enough. Once I get this displacement,
it seems that the only way of getting back to alignment is to run SilverFast
(SE), which does not have this problem, and somehow resets the scanner.
Anyway, the disalignment reappears after some time which makes Vuescan
rather useless for me that wants infrared dust removal.

I'll send a bug report to Hamrick (author of Vuescan) and hope that he'll be
able to solve this somehow

Regards,
Torbjörn

 

[Mike M. Miskulin]

While pondering the Universe, (e-mail address removed) (Torbjörn Einarsson)

Searched the archive and found that this type of problem was discussed
in the beginning of October, but anyway thought it might be good
reporting another occasion of the problem.

My problem is that VueScan (8.1.7 professional) produces IR scans which
are roughly 16 pixels (at 2400 dpi) displaced regards to the RGB
components (along the short direction of the scanner).
It does not happen always, but often enough. Once I get this
displacement, it seems that the only way of getting back to alignment is
to run SilverFast (SE), which does not have this problem, and somehow
resets the scanner. Anyway, the disalignment reappears after some time
which makes Vuescan rather useless for me that wants infrared dust
removal.

I've wasted quite a few hours the past week trying to track down what
appeared (to me) to be an issue with vuescan and higher dpi scans not
saving as 'cleaned'.

What appears to be happening is what you describe - a shifting of the IR
data so that the correction appears shifted as well. Under lower DPI it
either was not as noticable or not happening at all. Last night I noticed
the shift while comparing scans taken with vuescan on the PC vs those taken
using vuescan on my ibook. In addition, it seems that the problem has been
getting worse.

Initially I had done a few scans using the Epson and Silverfast SE programs
and using ICE. The resulting images were great but took forever. And as
I'm going to be scanning mostly medium and lf thats a lot of time! Also it
seems only vuescan was able to properly set up for batch scanning of
med/lf.

If you hear back from the developer please post a response here too.

Thanks

 

[Mike M. Miskulin]

I'm following up on my earlier post. Tonight I did a small experiment.
I used Silverfast SE to do scans at 600 and 1200 dpi with ICE on a 6x9
negative. I then used the Epson scan w/ ICE to do same at 2400 dpi. I then
used vuescan to do a 2400 scan w/ cleaning. While the alignment was not
100%, it was very close and drastically better than the night before. Or at
least good enough that the larger blemishes were mostly covered. The
smaller ones were still slightly out so that white was visable.

I may try doing a few more scans with the Epson driver w/ ICE and then try
vuescan again, perhaps doing multiple scans of the same negative to see if
(and how long) the calibration stays good.