Epson 700; pre scan and scan way off at high rez

[jvansoest]

I am scanning 4x5 color negs, mostly Kodak and occcasionally Fuji. I have been scanning at 1600 DPI (until recently), and it is useful to point out that with the V700 SF creates significantly sharper scans than the Epson driver.

I recently did a resolution comparison for 4x5 scans. I scanned the same image at 1600, 2400, 3200, and 4800. I frankly didn't believe I would get better results beyond 1600 other than what would arguably be called an interpolated scan. But I was pleased to be proven wrong. While the optical clarity of the scans (edge definitions) didn't change much, the noise level dropped in a big way making for much better scans over all. It was particularly gratifying to campare 1600, 3200, and 4800. The 4800 was much smoother and also had less fringing at contrast edges.

I have samples if anyone is interested.

However, I found another odd problem that I can't seem to fix. If I set a scan that works well at 3200 with good color balance and simply up the resolution to 4800 without changing anything the color in the 4800 scan fails. The red channel in particular gets amplified acrosss the image and the red contrast goes off usable range with highlights blocked at 255. I can't correct the color at pre-scan because there is no relationship anymore between the preview and the scan. The scan just goes red and contrasty regardless of any pre-scan adjustments or if I re-pre-scan or not

All filters are off, by the way. No Neg-Fix or sharpening, etc.. I am using a Mac with SF 6.4.4. One work around I have tried is trashing the scan profile and rebuilding it every time I do a scan. This only marginally improves the situation, there is still a big difference between the preview and the scan at 4800.

Color space is coordinated. Gamma matches. I am not sure what to do, because I really like the few 4800 scans I have successfully gotten. Does anyone have any thoughts?

Also switched to firewire and the scanner couldn't do the scans at all, just crashed. I am stuck with USB. Thanks for reading!

[LSI_Noack]

Dear jvansoest

although I have yet to encounter such an issue, I get the vague impression that something with the SilverFast settings files may have been corrupted.

Therefore, suggest you want to delete the "LaserSoft Imaging" folder (while SF isn't running) and check whether this does improve the situation.

On a typical Windows XP installation, the SilverFast "LaserSoft Imaging" folder is to be found at:
C: \ Documents and Settings \ (your username) \ Application Data \

On a typical Mac OS X installation, the SilverFast "Prefs" folder is to be found at:
/ User / (your username) / Library / Preferences /

However, SilverFast does provide a set of secure settings.
If it does not find a "LaserSoft Imaging" folder when starting up, it generates a new one with these safe values.

Best regards
Sonny Noack
- Manager Technical Support, LaserSoft Imaging AG -