Yellow marks in blues

Digital Camera Scanning
1

Heya I need some help to id what the cause of this is. I suspect it’s from the negative not being completely flat. Some negatives can have this yellow faint colour appear in the blues of an image, most notably in skies. I seem to get weirder colours with blues compared to the rest. Why I think it’s cause the film isn’t completely flat is because other negatives in the roll are completely fine. This will often be the start or end of a 3 frame strip but when the film has been cut to only 2 frames it seems there’s not enough to push it all the way through and keep it flat without it coming out the other side. Have others had this issue with this holder?

I scan with

  • GFX 50S
  • Pentax 645 macro
  • Valoi 120 holder
  • Raleno Light Table

I mask off all stray light with black cardboard.

nlp-yellow-tint-7
nlp-yellow-tint-71920×1516 2.33 MB

nlp-yellow-tint-6
nlp-yellow-tint-61920×1524 1.65 MB

nlp-yellow-tint-3
nlp-yellow-tint-31920×1533 2.54 MB

nlp-yellow-tint-2
nlp-yellow-tint-21920×2560 3.94 MB

nlp-yellow-tint-5
nlp-yellow-tint-51920×1525 1.91 MB

nlp-yellow-tint-4
nlp-yellow-tint-41920×1537 2.13 MB

nlp-yellow-tint-1
nlp-yellow-tint-11920×2395 2.61 MB

2

You can test your theory/suspicion by putting the negative on the backlight, without film holder. Use a piece of glass to flatten the negative. Then scan and check the outcome. If the streaks are still there, the cause lies somewhere else.

Can you see the streaks on unaltered RAWs or exported files that you convert by flipping the tone curves manually?

3

You could also turn the negatives through 180º and see if the position of the strange blemish alters. Are you positive that no extraneous light from within the room can reflect off the top surface of the negative, are they shiny side up?