120TF Banding Issue
PostPosted: Wed Mar 28, 2007 3:57 am
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)
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)