Hi, On 03/10/2016 10:10 PM, Denis Testemale wrote: > It even has a unit (eV) which itself is not dependent on the program. Ouch. You are mixing up exposure value and Electronvolt, totally different things https://en.wikipedia.org/wiki/Exposure_value https://en.wikipedia.org/wiki/Electronvolt
While EV might be defined properly during image taking conditions with aperture, time etc, it seems not to be defined properly for postprocessing. But I'm not familiar with this topic. Sebastian > 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] > > > -- > python programming - mail server - photo - video - https://sebix.at > cryptographic key at https://sebix.at/DC9B463B.asc and on public keyservers
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