Need help with purple/various color casts

Hi everyone! I keep having trouble to achieve consistent, accurate colors with NLP. I feel that the CCD exposure when scanning may be part of the problem, but in this case for example, the negative seems to have a pretty decent exposure according to the histogram. However, when converting this shot, I end up with a very strong purple cast out of the box. Even if I try to compensate for it manually (with relatively “extreme” slider movements in the white balance section), I still see an overall purple tint in the darker areas, and everything else getting close to “too green”).
All the photos from this roll show the same cast more or less consistently across the roll, so it’s not just on this one shot.
Does anyone have advice on how to consistently correct this, or maybe there’s something I’ve completely missed? Thanks a lot in advance!

About my equipment:

I’m running NLP 2.4.2 in LR 11.5. Using a Reflecta RPS7200 (same as Pacific Image PrimeFilm 7250Pro3) with Vuescan, scanning as RAW DNG.

Here’s the converted file (corrected):

And file straight out of conversion without adjustments:

Here’s the RAW scan in case it helps as well:
DNG scan file

I don’t have any advice for you sorry, but I did want to chime in and say that - at least in my experience - conversions with NLP always require a significant amount of tweaking/editing. Almost never have I converted a scan (I also use a film scanner) and felt it looked good right away. Negating color casts manually seems to be a huge part of the process.

Would love to hear others opinions and workflows.

I’d also love to hear about other people’s experiences, yeah! I feel like almost every time I see “striking good” results straight after conversion, it’s negatives that have been digitized with a camera instead of scanned, so maybe NLP is better optimized for camera raw files?
To be fair I haven’t tried V3 yet, so maybe the new roll analysis helps with more accurate colors.

I am on V3 and the roll analysis is an interesting feature, but in my case far from a magic bullet. Sometimes it is the better option, sometimes a single image analysis is a better option. I find myself checking both to see which suits a given image better.

I too wonder if the algorithms/analysis is geared towards camera scanning as opposed to film scanners…

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I found for best results do "shadow " priority for wb
But yeah, almost always color balance needs to be tweaked by eye.

Disappointingly, roll analysis didn’t do much for me in this regard either.

But it’s nice having control over the look. The next best thing would be to put it in PS and do a curve layer with auto white balance.

Good to hear some first-hand experience with the roll analysis feature! I’ll end up upgrading anyways because I think V3 has some nice QOL features as well, but it’s good to know so I can keep my expectations reasonable…

What do you mean with “shadow priority” for the WB, is that a preset inside the new NLP WB options?

Also that conversion looks pretty natural! But the shadows still look weirdly magenta, while the highlights have a slight green-ish tint.

Not sure if your guys’ scanners support individual LED color gains (like a Nikon) but I have been getting much better results by using the “super advanced workflow” in Vuescan which, essentially, negates the orange mask at the scan level by adjusting the color balance of the scanner’s LED. I am also scanning the negs as “color negative” but still saving as raw. This outputs a negative image, but bakes in the film base color correction.

Some info on the process here:

With this process I don’t even white balance in LR, I just convert the negs with NLP. Results have been much more neutral.

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