Microtek FilmScan 35 Noise and Banding issues

[mjb]

I've recently acquired a Microtek Filmscan 35, bundled with Cyberview. The host application is GIMP in all of the following description, with Silverfast SE6.0.1.r10, under W98 SE

Having quickly found out that Cyberview is apparently incapable of reliably producing a scan that matches its own preview output, especially on negatives, I switched to SilverFast SE.

The demo seemed to work well, apart from the "Watermark" -- the words Lasersoft woven into the picture + a load of background noise.

On registering the driver, the text disappeared but the noise grain remained. Uh-oh ... that's not part of the watermark. That's actual noise.

Problem 1)

Comparing the output of Cyberview and Silverfast, on transparencies, there is a noticable quality reduction (Y-M-C grain) through Silverfast. Cyberview is slow to scan in "Quality" mode, quicker in "Normal" mode. Silverfast is one uniform speed, no matter what mode I select. Cyberview produces a cleaner scan in "Quality" than "Normal". How do I get the quality mode up in Silverfast, when the tickbox for "Scan as draft" and "Preview as draft" make no difference to the scan speed/quality?

Problem 2)

Also, on dark transparencies (light areas of negatives) there is fairly bad horizontal banding, as if the brightness or contrast is stepping up and down over groups of lines. It's always horizontal, it's always different from scan to scan. It's there in Cyberview, Normal mode, but gone in "Quality mode". Again, I think I need to get quality mode switched on for Silverfast to be any use, but I can't seem to do it.

Problem 3)

Finally, does anyone understand the internal operation of SilverFast/Negascan that causes it to behave differently (mechnically) on different scans? Mounted transparencies are scanned in one fairly smooth pass. Negatives, OTOH, have a little "prescan" look done at the top of the frame, before scanning commences. What's that about? Because on some films, Negafix seems to get a bit confused, and adds bright R-G-B sparkly "dust" into dark areas of the picture (light areas of the neg).

Bizarrely, covering up the sprocket holes with thin card stops it doing this extra "look", and gives a sparkle-free scan. I'm confused as to why this helps.

Is Negafix looking for sprocket holes? Is it meant to be able to see them to operate correctly, or is the fact that they are visible confusing it?

Any advice on the above appreciated! I really need the quality of scan of Cyberview with the colour management (and ability to provide a scan matching the preview!) of Silverfast ...

[mjb]

The banding problem above is shown in these examples -- they are the same negative, scanned 3 times in succession with exactly the same settings, in Silverfast. It seems that colour casts change from scan to scan, especially if the scan is dark. The banding varies from frame to frame, as can be seen below.

This banding doesn't happen in Cyberview. I'm still looking for a way to get Silverfast to produce a quality scan (not a draft). I've updated the SASPI dll but it didn't improve this at all.

Anyone with ideas to fix it, or can affirm that this happens on their setup? Or can Silverfast just not work properly on the Filmscan 35?