VueScan raw files are stored as TIFF format, by default, with no film correction or gamma processing. They're essentially raw scanner data represented in a TIFF file organization. When you set the option to output as DNG, the data is reorganized into the DNG standard linear-RGB representation.
When you tell Lightroom to flip the image, and save that metadata back to the DNG file, it's not changing the raw data in the file, it's just adding a 'processing parameter' metadata block available to other programs that know how to interpret it. This means that if you use othe Adobe aware products to later process you're DNGs you'll be fine, but if you're going to use other software that only reads the standard DNG data, the images will still be flipped incorrectly. (Personally, I see no point to using Lightroom just to flip the data around and then NOT using Lightroom to do the raw->RGB processing, but I feel it's important that one understand what's going on.) If John really wants to get the raw data oriented correctly, the only solution is to re-scan the slides. It would be inconsequential to me since I use Lightroom to do 99% of all my image processing. :-) Godfrey > On Sep 20, 2014, at 4:31 AM, Zos Xavius <zosxav...@gmail.com> wrote: > > DNG from scans typically just contains an embedded tiff. You really > aren't rendering from raw data like say from a camera. Its not raw > data really. DNG is just a container really, much like a few image > file formats and many of the various video file formats. What makes > DNG kind of useful with scanning is that you can just run the results > through ACR and apply color profiles and what not. Once nice thing > about it is that it will save your adjustments in metadata. As > everyone has said lightroom will rotate the image and which probably > just changes the rotation flag in the dng. LR is kind of nice in how > it doesn't really do much to the original files other than update > metadata and you can turn that off too if you're really paranoid. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
