LIGHTROOM Purple/magenta cast in highlights for photos taken with the Leica D-LUX Type109

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  • Updated 3 years ago
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Photos taken with the Leica D-LUX Type109 (and I suspect Panasonic LX100) show a strong purple/magenta cast in highlights, when using the extended ISO range ISO100. The problem disappears when disabling the extended ISO range and shooting at ISO 200. The attached screenshot shows an examples comparing photos with and without extended ISO range, shot at +1,7EV and then corrected -1,7EV in Lightroom.
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Carsten Kostrzewa

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Posted 3 years ago

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Steve Sprengel, Champion

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Can you provide the raw file, above, and a very overexposed raw file that is pure white, both shot in the mode that produces the magenta, something for Adobe to measure the white-point of?

Use something like www.dropbox.com and post a public share link to the files.
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Carsten Kostrzewa

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I uploaded both photos above to dropbox (hope that works):
https://www.dropbox.com/sh/dgky134dgd...
Both were taken with +1.7EV, as mentioned one in extended ISO range at ISO 100 (magenta cast), the other one having the extended range disabled and shot at ISO 200 (correct highlights). Both should have sufficient highlights with pure white. When converting the same ISO100 RAW file in camera, there is no magenta cast, which makes me believe that this is an issue of the Adobe RAW Converter.
I have searched the web, and other people have reported the same issue, see e.g.:
http://www.dpreview.com/forums/post/5...
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Steve Sprengel, Champion

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Please upload a maxed-out-white image. One that is 30secs long at wide-open aperture of a brightly lit plain subject would be the best, like sun on a piece of white paper or similar, or perhaps a cloudy sky mid-day.

The maximum values for the sky in your image aren't nearly the same and at around 3000 are only about half-way between the maximum 11-bit value of 2047 and the maximum 12-bit value of 4095.

Here is what RawDigger, a raw-analysis program, shows for the maximum values:
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Carsten Kostrzewa

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Ok, got it. I have now taken two photos from today's overcast sky, both exposed for 1s using f/1.7. That's probably something like +12stops overexposed. Hope that's sufficiently overexposed.
https://www.dropbox.com/sh/q1pn6qwsph...
L1000275.RWL extended ISO range, ISO 100
L1000276.RWL extended ISO range disabled, ISO 200
Same problem: the first one shows a non-uniform purple cast, only the corners are white. The latter is fine, i.e. white across the whole photo
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Steve Sprengel, Champion

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Interestingly RawDigger shows the same magenta-in-the-center as ACR and it probably should have been exposed twice as long as the ISO 200 one, but perhaps Adobe can use it:
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Chris Castleberry, Camera Raw Engineer

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Carsten and Steve,

Thanks for reporting this. I've logged a bug for our engineers to investigate.

Regards,

- Chris
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Carsten Kostrzewa

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Steve, yes you are right, it should have been exposed twice as long. I did this in a hurry in the morning and forgot the adapt the setting. But I hope the exposure is still long enough.
Chris, thanks for taking this up. As said, for now I have simply turned off the extended ISO range and everything is fine. However it would of course still be nice to be able to correct the photos, that I have already taken until now.
Regards,
Carsten
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Carsten Kostrzewa

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Adobe Camera RAW Converter 9.0 appears to solve the purple cast issue, however now the photo appears 0.5 EV to 1EV overexposed. See also http://gsfn.us/t/4q2tc