I’m hoping someone can help point out where I’m going wrong. In some images, particularly ones that have large areas of dark tones near the edges, I’m getting conversions with a red/orange glow in the dark tones. You can see it pretty clearly along the bottom edge of this image, particularly in the bottom right corner:
Replying to myself because I can only insert 1 image:
I’ve found that increasing the border buffer reduces the red/orange tint dramatically (it actually changes the overall color of the image pretty dramatically). This is what it looks like if I increase the border buffer to 25%:
It still needs a little brush work to remove the last bit of red, but it’s generally much better.
And one last post:
I’m cropping in to the image area before doing my conversion, but even if I don’t crop I see the same thing. In fact the red/orange appears beyond the image borders, I’d expect the film base to be completely black:
Any ideas on what I might be going on?
This is caused by vignetting and is very easy fix. See this thread: Orange bleed at edges of scans! Need help!
Thank you for the link! So I went back and carefully reshot this roll of film, plus a photo so I could use the flat-field correction. And the results were dramatically better. The colors of the positives are, overall, better across the board.
Except I’m still seeing red casts in the shadows of the same images. This time, to test how vignettes were affecting things I shot the image twice, once with the film rotated 180 so that the vignette would land on different parts of the image. But the positives look more or less exactly the same on both images.
I’m cropping just to the shadowed, asphalt area so it’s more obvious:
You can see the red bleeds out beyond the image areas into the gap between frames (I haven’t flipped either image so you can see how the orientation of the negative doesn’t impact the outcome of the conversion).
At this point I may just be being pedantic, I can knock the last bit of cast off by playing with the various color controls. It just seems odd that the cast/bleed only appears in some of the photos, and the location of the cast is consistent in the photograph irrespective of the orientation of the frame when scanned.
I am having the exact same issue and can’t figure out what’s going on! I’m certain my lighting is even and also tried what you did with rotating the negative 180 degrees but the problem persists… dark corners have a strong orange cast coming in, typically in the same bottom corner.
Have you had any luck? I also think sometimes I’m being pedantic but when I compare next to lab or flatbed scans the difference is really noticeable.
Another thing i’ll say is that I notice the same if not worse when scanning 120, which begs me to wonder if the issue is vignetting, given that the corners of my 6x6 negative are actually in quite a bit from the corners of the DSLR sensor… I wonder if it is an issue with NLP itself.
Will try flat field correction next but i’d like to get to the root of the problem.