Am Donnerstag, 10. März 2016, 22:10:32 schrieb Denis Testemale: > The only setting present in the xmp files is the exposure compensation, > nothing else. And for that matter, you can also get xmp files for Aftershot > program (that is something that I asked to the developper and he did it). > The only differences between those 2 xmp files are the xmp fields (so that > they can be read by the target softwares), the exposure compensation value > is the same. Which makes sense to me since exposure is an absolute value, > not dependent on the program. It even has a unit (eV) which itself is not > dependent on the program. So when I say that the xmp files are "for > Lightroom" it only relates to the xmp fields.
[...] > xmlns:crs="http://ns.adobe.com/camera-raw-settings/1.0/"; > crs:Exposure2012="0.29048"> As the namespace of that value indicates, it's an Adobe Camera Raw setting, which is most likely using the same exposure math as Lightroom. Therefore I assume that the value put there is meant to be read by those programs. And iff these need some scaling to be getting identical results in darktable then that should also be applied here. Of course, there are several assumptions that I can't verify as it would need access to Lightroom on the same computer (so the screen, display profile, ... doesn't affect the results) and some time and determination: - Lightroom settings really need the scaling. From what I remember having read in the past in comparisons between dt and Lr was that their default exposure differs. So it might very well be some extra exposure that we should add and then using the Exposure2012 verbatim ontop in a second instance. - The people who created the timelapse thing that creates your XMP files actually tweaked the settings to give correct results in Lightroom and not just dumped some numbers into that field. In that case we would have to take the numbers verbatim, no matter if Lightroom actually needs scaling. [...] > The exposure compensation is the same. Once imported, the luminosity of the > images is smoothed and the timelapse doesn't flicker. And it doesn't matter > if the image imported in Lightroom, Darktable, or Aftershot looks > different: that can be corrected differently (levels, curves, basecurve, > etc.). Do you have access to Lightroom to try if the values as given result in a constant exposure? > Hope it's clear. > Cheers > denis Tobias [...]
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