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.
Let me give you an example of 2 xmp files generated for the same picture, one is Lightroom-compliant and the other one is Aftershot-compliant: Lightroom: <x:xmpmeta xmlns:x="adobe:ns:meta/" x:xmptk="Adobe XMP Core 5.5-c002 1.148022, 2012/07/15-18:06:45"> <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#";> <rdf:Description rdf:about="" xmlns:crs="http://ns.adobe.com/camera-raw-settings/1.0/"; crs:Exposure2012="0.29048"> </rdf:Description> <rdf:Description rdf:about="" xmlns:lrt="http://lrtimelapse.com/"; lrt:ExternalExposureDefault="0.29048"> </rdf:Description> </rdf:RDF> </x:xmpmeta> Aftershot: <x:xmpmeta xmlns:x="adobe:ns:meta/" x:xmptk="XMP Core 4.4.0"> <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#";> <rdf:Description rdf:about="" xmlns:dmf="http://www.bibblelabs.com/DigitalMasterFile/1.0/"; xmlns:dmfversion="http://www.bibblelabs.com/DigitalMasterFileVersion/1.0/"; xmlns:bset="http://www.bibblelabs.com/BibbleSettings/5.0/"; xmlns:blay="http://www.bibblelabs.com/BibbleLayers/5.0/"; xmlns:bopt="http://www.bibblelabs.com/BibbleOpt/5.0/"; dmf:versionCount="1"> <dmf:versions> <rdf:Seq> <rdf:li> <rdf:Description dmfversion:software="bibble" dmfversion:softwareVersion="2008.1" dmfversion:versionName="_DS33900.NEF"> <dmfversion:settings> <rdf:Description bset:settingsVersion="66" bset:respectsTransform="True" bset:curLayer="0"> <bset:layers> <rdf:Seq> <rdf:li> <rdf:Description blay:layerId="0" blay:layerPos="0" blay:name="" blay:enabled="True"> <blay:options bopt:exposureval="0.29048" bopt:autorotate="0" /> </rdf:Description> </rdf:li> </rdf:Seq> </bset:layers> </rdf:Description> </dmfversion:settings> </rdf:Description> </rdf:li> </rdf:Seq> </dmf:versions> </rdf:Description> </rdf:RDF> </x:xmpmeta> 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.). Hope it's clear. Cheers denis Le 09/03/2016 12:09, Tobias Ellinghaus a écrit : > Am Mittwoch, 9. März 2016, 00:07:06 schrieb Denis Testemale: > > Thanks for the answer. > > I don't know for LR, I don't have it. I can understand that you try to match > > exposure between LR and DT for the situations where users want to import > > images and their treatment in DT, and not have to tweak the results too > > much to obtain what they had in LR. The problem I see with this method is > > very specific to the use I have of the xmp files (timelapse with the > > Ramperpro controller): those xmp files and the exposure correction they > > convey are used to smooth the exposure over the series of images. Indeed, > > since the cameras, when not in bulb mode, use 'discrete' exposure time > > (say, 1/100s, 1/80s but not 1/90s for example), those exposure corrections > > compensate for that and smooth the exposure all along the series. So, if > > the exposure compensation is modified, I suspect (but have not checked, > > yet) it's going to ruin the objective. I hope my explanations are not too > > confusing. Anyway, this is certainly a border case, and you should favor > > the majority of use cases: make the import from LR to DT consistent. > > I would assume that when a device generates an XMP file with Lightroom > settings > it is using values adapted to that target software. Otherwise their settings > would result in wrong exposure in the intended program. > > [...] > > Tobias > ____________________________________________________________________________ darktable user mailing list to unsubscribe send a mail to [email protected]
