Microtek ScanMaker 9800XL slow with Silverfast Ai 6.4.1R4B

[maru]

INTRO:We have purchased at work the A3 flatbed Microtek ScanMaker 9800XL. Along with it came Silverfast Ai 6.4.1R4B. We needed Ai mostly for the calibration feature, since we want to digitize old documents, photos, art work and we want to make sure the digital image files are an exact copy of the original.

PROBLEM:
Microtek Scanwizard Pro, when making NO correction to the image (i.e. descreening) takes about 1 min to scan a white A4 page at 300ppi 24-bit colour and 3min 50sec to scan it at 600ppi. For the same paper, in Silverfast Ai with NO filter at scan type 48->24, it takes about 6min 30sec to 7min 30sec for 300 dpi and 28min30 to 30min for 600 dpi 48->24.

Questions
1. Could one option in Ai make all this difference or is there NO way to reduce this time in Ai?

2. Is there a difference in the quality of the image if we produce it through ScanWizard Pro having calibrated the scanner (Kodak Q60) instead of Silverfast Ai using the calibration feature?

Maroussa

[maru]

After explaining the scanner's behaviour to the Technical Support, we were told that the scanner must have been multisampling (no idea how we made it do that)... Reseting all options back to factory settings (shift key pressed over the options button) solved the problem .

Thank you Mr. Jan Rossee..

Maroussa

[tzickric]

I just purchased a (used) Microtek 9800XL that came with its SilverFast Ai software. I installed that version and tried it out, and did not notice any unusual behavior. However, tonight I upgraded the software to the 6.4.5r4b level, first uninstalling the old version as advised after the download. Now, when I attempt to scan, it takes several minutes for the scan to complete, regardless of the requested scaling or resolution.

I followed the suggestion in the first response here, and found that the problem indeed went away as advertised. However, I discovered how to make it happen again. When I enable Descreening, the scan time increases dramatically over when Descreening is not enabled. When Descreening is disabled, a 12x12 scan at 150dpi takes perhaps a minute at the most. When Descreening is enabled, the scan takes many times that. And in addition, after the scan is complete, the actual descreening process is terrifically slow, and CPU utilization by the SilverFast software shoots up to 98% (does not play well with others).

I did a scan of my 12 inch by 12 inch object, reduced to 5 inch by 5 inch at 150dpi with descreening turned on, and after the scan finally finished, the descreening process on this approximately 2MB file took 12 minutes.

Could enabling descreening somehow be enabling multisampling for this scanner? I found no option in any of the menus to enable such a feature, so have no idea if it can be turned off other than to disable descreening. Any suggestions would be welcome, for either the slow scan time, the even slower descreening time, or both!

Thanks much,
Terry Z.

[LSI_Muenier]

Dear Terry,

SilverFast's Descreening must be able to "see" the screen pattern, and, thus, scans at a higher resolution that your desired output resolution of 150dpi might signal. This high resolution results in longer scanning time.
When switching Descreening off, you again have a "normal" scan at 150dpi with quicker scan performance (but possibly with a moiree, which was eliminated by the Descreening, before).

Best regards,
Martin

[tzickric]

Thank you, Martin. I continued to dig around and found a similar explanation in a different post earlier, but am glad to have it confirmed. The results are worth the wait, as everything I've scanned has come out beautifully.