tournesol

:) OK, so this is not smog. To demonstrate this more clearly, I have attached a new image where you clearly see the 3-4 vertical bands across the image. How would you suggest I apply the hue adjustment? I'd have to paint a mask using brushes, I assume - if I just apply the adjustment uniformly to the whole image it will not deal with the issue, and will impact the rest of the image in an unwanted way.

I am scanning old negatives with my Coolscan V ED. On many of the negatives, I am getting banding or patches of (most often yellowish) discoloration. I suspect this is a result of the negatives having been stored under too warm conditions. An example of the discoloration can be seen in the attached image - it is a yellow band going across from left to right, on top of the tree and sky. I am looking for any tips/hints from people about methods I could use in post-processing to reduce or remove these colour casts. I have experimented with some techniques in darktable but not found one that works well. Happy to take example techniques from folks for other software as well, I am sure I can adapt them to darktable also.

I have just revived my Coolscan V ED and would love a copy of the pdf. Could someone post a copy here as an attachment? Alternatively, please upload it to Dropbox using this link: Dropbox - Submit files Many thanks!