Troubleshoot - issue with 4x5 film scans using mirrorless

[ZhanTeh]

Occasionally some of my 4x5 digital scans would have this issue of small blue streaks showing up across the scanned image. I checked the negatives through a loupe and do not see any scratches so I assume it is a problem with my scanning process.

I am wondering if the forum would have any idea what causes this and where in my process should I start troubleshooting?

Some details on my process:

• 4x5 developed in Stearman Press SP-445
• Scanned with Fuji X-T5 with adapted Carl Zeiss 60mm macro lens on LED light panel
• Four shots stitched together on Lightroom and later converted using Negative Lab Pro

Important to note it only shows on some scans, not all. Any advice would be appreciated.

*Please ignore the color streak , I was being cheap and used old developer

 

[koraks]

I checked the negatives through a loupe

Are you sure? Did you also inspect the backside of the film?
These really do look like scratches to me, not a scanning artifact.

 

[MilesL]

If you rotate the negative 180 degrees and scan again, the scratches should show up at a different place, if it were an issue with the scanner, correct?

I've had scratches that don't show to the naked eye, but when light hits in the right angle, they will show.

 

[ZhanTeh]

Are you sure? Did you also inspect the backside of the film?
These really do look like scratches to me, not a scanning artifact.

Went back under the loupe this time going through the flip side as well and sure enough - scratches on the film.

I suppose now I need to change the way I load and unload film in the dark bag and see if it improves.

Thanks for the insight.

 

[koraks]

Thanks for checking! Dark bags can be a little tricky since they're a bit cramped. Well, recognizing the problem is the most important step towards solving it!