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120TF Banding Issue

PostPosted: Wed Mar 28, 2007 3:57 am
by deldridg
Hi folks,

I have been noticing banding on my scans (see <a href="http://tinyurl.com/2cdmpq">here</a> - note 261kb) using both Silverfast and ScanWizard Pro. If you throw this image into PS and cycle through the RGB channels (Ctrl-1, Ctrl-2, Ctrl-3 etc.) you will see clearly where the bands are.

Some characteristics of the banding:
- only happens across the line of film (ie. perpendicular to the holder travel)
- happens with all film holders (35mm strip, 35mm mounted, med-format)
- is random in intensity ? some scans have no evidence.
- RGB channels have bands that do not line up when you cycle through them
- happens at different scanning resolutions
- occurs in both negative/positive scans
- bands are also visible on Greyscale scans
- has happened on 2 separate computer systems (so it is not related to the computer hardware)

The ultimate result of this banding is to create unsharp bands across the image. Typically, these are about 100 pixels apart and are about 100px wide (on a 4000dpi scan).

Sadly this is likely to cost me dearly in time as it appears the scanner may require sending away, perfectly timed for an upcoming exhibition I am preparing for.

If anyone has any suggestions on the likely cause/solution, I would greatly appreciate it.

Many regards,
David E (Sydney)

PostPosted: Wed Mar 28, 2007 2:12 pm
by LSI_Leschke
The first thing I which comes to my mind is to check whether the scanner has the latest firmware on it. There were updates available for this model- please contact Microtek for further information.

PostPosted: Wed Mar 28, 2007 2:29 pm
by deldridg
Many thanks for your response. Indeed I have done a check and I have the current firmware - Ver 1.8.

It's a bit of an odd one and the random nature of the issue means it could be harder to resolve.

Fingers crossed there will be a solution soon - hopefully a painless one!

Regards and thanks,
David E (Sydney)

PostPosted: Wed May 02, 2007 9:30 am
by LSI_Muenier
Dear David,

looking at the image you provided, I also see an offset between the RGB color channels. I haven't this with our sample unit. Could it be a mechanical problem inside your scanner?

Best regards
Martin

PostPosted: Mon May 07, 2007 2:47 am
by deldridg
Hi Martin,

many thanks for your response. In answer to your question, this issue only happens with Silverfast but not with other scanning software. The main testing with alternative software has been with Scanwizard Pro, shipped with the scanner and each channel is identical.

This leads me to believe that the issue is not a hardware problem.

Many regards,
David Eldridge

Re: 120TF Banding Issue

PostPosted: Wed Jul 15, 2009 5:05 pm
by stevelee
hello
I realize that this post is 2 years after Deldridg's, but I would like to know if anyone finally found the solution to the soft banding problem on the 120tf/sprintscan 120. I use a Polaroid Sprintscan 120 with the microtek chip intalled (v 1.70) - so it thinks it is an artixscan 120tf. I have tested 4 different software: Silverfast, v**s**n, Sprintscan, and ScanWizard Pro (all lastest versions possible) and I found that the blurry band occurs with all, with the exception of ScanWizard Pro when used in grayscale. The distance between bands decreases as the resolution increases. It is my observation, when watching the movement of the holder during a scan, that the banding occurs when the holder moves back out slightly at each pass. This movement does not occur when ScanWizard Pro performs a grayscale scan. This leaves me to conclude that it is both a hardware and a software problem!
Has anyone found out more?

Re: 120TF Banding Issue

PostPosted: Fri Jul 17, 2009 1:11 pm
by LSI_Muenier
Dear Steve,

unfortunately I could not reproduce this behaviour with our sample scanner, but, as you observed it with several softwares including SilverFast and ScanWizardPro, I conclude that the scanner firmware produces the problem when the scanner is in start/stop mode as you described.
Only thing I can think of is to fetch the image data as fast as possible from the scanner, i.e. in SilverFast: to use the HDR scan mode.

Best regards
Martin

Re: 120TF Banding Issue

PostPosted: Wed Aug 12, 2009 5:10 am
by WhiteBird
I did have a similar banding issue on an i900. I traced it to unequal light emission from the tube across the width of the scan. The inequality originated in the aging and tight curling of the white plastic reflective sheath lying behind the tube, which was localized along the centre line of the scan.

The cure necessitated the dismantling of the tube assembly and reshaping of the white plastic under heat so it did not curl near the tube. I have had no bands since then.

Bear in mind that Microtek no longer sells scanners and that they did not offer repairs or parts even when they did. So any mods we do are in the interests of prolonging the usefulness of a machine which we know and for some reason wish to keep using.

IMO it would be cool if Lasersoft would provide a deeper than usual discount for those of us forced to replace an orphan Microtek.

Re: 120TF Banding Issue

PostPosted: Wed Aug 12, 2009 10:06 am
by LSI_Muenier
Dear WhiteBird,

thank you very much for your technical hints!

Best regards
Martin