Hello All,
I have a huge library of slides scanned with a Nikon LS-5000.
When I open the files (DNGs) with DT, the colors seem consistently off, like if the WB was not recognized, however there is an entry in the repository for this scanner.
Do I have to enter some specific info in DT when I load these files?
Thanks for reading,
and Merry Christmas to all of you,
-Gian
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It would help if you could post a sample file.
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I thought they would be too large to upload (111Mb)… can I?
You can share via Dropbox or similar.
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I think the max. size is just under 100MB. Would you be able to upload somewhere like Google Drive, WeTransfer or similar?
Edit - @paperdigits beat me to it! 
this is the DNG:
and this is the JPG that is directly produced by the LS-5000.
DT loading the DNG complains about “failing to read camera…”, and the mud looks blue.
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DT uses WB values of 1 for all channel so its not reading WB for these DNG or they are uniWB??
THe only reference to white is an XY white point … I am sure someone quite familiar with DNG files might be able to give you some insight but I don’t think this file is following convention…
that’s exactly what I see in DT
I don’t know much about this stuff… but thank you for the file.
I can get a reasonable looking result by first switching off color calibration (if on) as it relies on a correct reference value from the WB module, then setting WB manually by using the eyedropper on the image.
But the sky is very reddish compared to the jpg. I don’t whether that’s due to the WB issue, or just due to whatever processing was applied to create the jpg.
Hopefully someone else will have some input. As @yasuo found the same result in Adobe, it seems to be more of an issue with the file rather than a dt issue. Perhaps.
[edit 5 min later]
I was able to get closer to the look of that jpg by leaving the WB at the default (blue) settings and using rgb curves instead. This is not an ideal workflow as at least with the default module order the effect of the curves is dependent on the exposure setting, among others. Still, it makes me wonder if the scanner software was simply doing some curves/levels style adjustments, as opposed to a traditional white balance operation.
F039-12.dng.xmp (11.8 KB)
I’ve now moved the rgb curves module’s pipeline position to before exposure - this actually seems a practicable approach, and looks quite decent (at least similar to the jpeg) after a bit of fiddling. I just don’t know if it would carry over to other images though.
F039-12.dng.xmp (13.9 KB)
thanks, I appreciate your effort, but since I have about 12K slides scanned, I would like to find how to get correct colors right away, and then do the usual minor edits.
I think that it must be some info missing in the DNG, since it seems other RAW processors get that blue cast.
I wonder if this can be fixed in the Input Color module.
Are they all blue dominant?? From what I can see is there is no good correction in the embedded profile or any wb multipliers in the metadata. You might be able to calibrate the scanner and make a profile that helps but I am not sure how many lighting conditions your 12K photos have and how broadly that could be applied…
well, more or less blue… but the JPEG produced by the LS-5000 are substantially correct.
The LS-5000 is listed on https://raw.pixls.us/, so why RAW processors do not interpret colors correctly?
sorry if these are silly questions…
What about:
Is there a way to use such a target on Linux?
With an appropriate ICC profile, can I use it in DT Input Color module?
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Not silly… you can use a program like this to make an icc profile…
https://rawtherapee.com/mirror/dcamprof/dcamprof.html
Or even just argyll…
Snippet from a web link…
Mac & Linux
Our recommended Mac & Linux solution is a software called ArgyII which you can download and install for Mac or for Linux. You’ll also need to download and unzip the ZIP file tied to the Charge Number in the lower right corner of your IT8 card if you ordered it from our recommended vendor. Scroll to the bottom of that page and look for your charge number and download and extract the ZIP file. You’ll need the .txt file with the same Charge Number from this for calibration. Now open up a command prompt and browse to the directory where you have stored your RAW IT8 scan and the .txt file.
Run the following command:
scanin (your-it8-scan).tif it8.cht (charge-file-number).txt
That should output a .ti3 file that should have the same name as your TIF file, you’ll use this in the next step.
Next, run the following command:
colprof -D
If all goes well that should output an ICM file in your Argy folder and you now have your IT8 profile! Congrats!
If you have a Mac you want to place it in /Library/ColorSync/Profiles/ for it to show up in your image editor of choice.
For Linux it’s usually placed in one of these places -
/usr/share/color/icc
/usr/local/share/color/icc
/home/USER_NAME/.color/icc
thanks Todd!
That target looks useful - I didn’t know you could get those. (never looked I guess!)
Dcamprof is good I believe.
I’m on Windows and use LumaRiver Profile designer which is a paid GUI version based on dcamprof for Windows and Mac.
I’m no expert (obviously!) but it makes it fairly easy.
If you get a target slide, I’d be happy to run a target shot through and create an ICC input profile, if it helps at all.
thanks, Steven, I’ll try to find one
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The white balance coefficients should be constant per film. In contrast to digital images, you don’t need to separately white-balance each analog image. So you could make a single preset for the slide scanner, and apply it to all images.
Or perhaps you’ll need to make one preset per film stock. This sort of depends on your artistic goals.
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