RPS 7200 shows stripes when using dust removal

[joshlac]

Hi,

The Reflecta RPS 7200 infrared dust removal causes stripes visible on blue and green channels, please see samples below:
1. With IR dust removal - blue channel:

With IR dust removal - blue channel.jpg (275.03 KiB) 2337 mal betrachtet

2. Without IR dust removal - blue channel:

Without IR dust removal - blue channel.jpg (274.78 KiB) 2337 mal betrachtet

Is there anything I can do to fix it?

[Jossie]

Which software did you use?

Was this a B&W-negative? If so, scratch-and-dust-removal does not work for most emulsions due to the high silver content.

Hermann-Josef

[joshlac]

I used demo version of Silverfast. The issue is present with CyberViewX as well.

The negative is colour Agfa, please see the photos below in colour:

1. With IR:

With IR dust removal - RGB.jpg (293.17 KiB) 2314 mal betrachtet

2. Without IR:

Without IR dust removal - RGB.jpg (425.09 KiB) 2314 mal betrachtet

[Jossie]

Good morning,

which settings did you uses for iSRD?

Please do not use the automatic mode but adjust the sensitivity manually.

Strange is that you only see the stripes in the B-channel.

Could you make a scan in the 64bit HDRi-mode at resolution (not preset!) 3600 ppi as TIF available (e.g. via filebin.net) so I can take a look at it?

Hermann-Josef

[joshlac]

Hi,

I did two sample scans with different frame with the settings you requested: 3600 ppi, 64Bit HDRi RAW saved as TIFF:

https://filebin.net/fma9yx3q44uqu5sn

https://filebin.net/4ytnznn6oe4apr8u

Thank you for your help and please let me know what to do next.

[Jossie]

I downloaded the fiels. I hope to be able to take a look at them by tomorrow.

Hermann-Josef

[joshlac]

Ok, I did two more scans without IR dust removal at different ppi's and the banding is there:(

At 2400 ppi the vertical banding is barely visible, however I can see some horizontal banding now:
https://filebin.net/jfk9xbcvmuag51kn

At 3600ppi the banding is very visible:
https://filebin.net/us8utl35zil00t4g

I did use different USB cables, I even tried FireWire connection, different power supplies (directly to power socket) and still I cannot get rid of the banding. It might be something wrong with CCD or capacitors?

[joshlac]

Finally, I scanned same frame using the same PC system, USB cable and power supply, but with other Reflecta scanner, ProScan 7200.

The scan is way better with no banding at all:
https://filebin.net/pvaac7eqymootep2

Looks like the old RPS 7200 is having hardware defect I cannot diagnose:)

[Jossie]

The stripes are there also in the G-channel. I do not see any in R.

Try to make 10 dummy scans, then turn the scanner off and on again to force a new calibration. Are the stripes still there if you make a scan after this procedure? Maybe the scanner is quite temperature sensitive and the calibration taken in cold state is no longer valid after warm-up. In any case it is worth a try.

The stripes are definitely not due to iSRD.

Hermann-Josef

[joshlac]

Hi,

I did 10 scans and previews, turned the scanner off and on and the stipes are still there

First scan:

scan 1.jpg (282.75 KiB) 2152 mal betrachtet

11th scan after power cycle:

scan 11 after 10 scans and power off.jpg (281.91 KiB) 2152 mal betrachtet

[Jossie]

Too bad, but it was worth a try.

Hermann-Josef