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NegaFix: How to avoid saturation?

PostPosted: Thu Nov 12, 2015 7:10 pm
by Jossie
Good evening,

several of my scans of color negatives saturate in the R-channel and I am looking for a way to avoid that. I guess, this is a problem not specific to my films but is of general interest.

For positives it would be trivial, since I could reduce the analog gain. However, the analog gain is deactivated for negatives (I assume to keep the reference to the NegaFix profiles).

One would think that an obvious way out would be to scan the negatives with film type set to positive into a raw file and then, once loaded into HDR, switch to NegaFix there. I tried that and first compared the raw files, the one scanned with film type positive to the one scanned correctly with film type set to negative. As expected, the two raw files are identical (to within the noise), since they are raw files.

However, the colors obtained in HDR from the positive scan are markedly different from the colors obtained in the "regular" way, i.e. scanned with film type set to negative:

Vergleich_pos_neg.jpg
Vergleich_pos_neg.jpg (123.62 KiB) Viewed 1456 times

So I have two questions:
1) Why does one get different colors, if the raw files are identical? What do I do wrong?
2) Since the workflow described above does not seem to work, how can I avoid saturation in scans of color negatives?

Hermann-Josef Röser

Re: NegaFix: How to avoid saturation?

PostPosted: Tue Nov 24, 2015 3:43 pm
by LSI_Ketelhohn
Dear Mr Röser,

Did you execute the image auto adjustment in HQ Preview mode.
The result of the automatic can be different on the lower resolution preview, simply because a lower number of pixels are available.

Kind regards,
Arne Ketelhohn.

Re: NegaFix: How to avoid saturation?

PostPosted: Tue Nov 24, 2015 4:41 pm
by Jossie
Dear Mr. Ketelhohn,

the images are screenshots of PhotoShop diplaying the files as saved to disk without any adjustments whatsoever, not even a NegaFix-profile had been applied.

But unfortunately you do not address my main issue at all: How to avoid saturation in scans of color negativ films.

Hermann-Josef Röser

Re: NegaFix: How to avoid saturation?

PostPosted: Mon Dec 07, 2015 3:19 pm
by LSI_Ketelhohn
Dear Mr Röser,

I will have to solve that through our support system.

Kind regards,
Arne Ketelhohn.