asfeir Posted October 26, 2007 Share #1 Posted October 26, 2007 Advertisement (gone after registration) I noticed that if one exports M8 files in lightroom using export to dng lossless compression, one gets files that are about 5 to 6 MB down from 10. Any information on how this can be? are we losing anything in this operation? If not, it is worthwhile doing it to save disk space Link to post Share on other sites More sharing options...
Advertisement Posted October 26, 2007 Posted October 26, 2007 Hi asfeir, Take a look here Lightroom Export DNG. I'm sure you'll find what you were looking for!
asfeir Posted October 26, 2007 Author Share #2 Posted October 26, 2007 sory, forgot to mention: Working on MacBook Pro using Lightroom 1.2 Link to post Share on other sites More sharing options...
sandymc Posted October 26, 2007 Share #3 Posted October 26, 2007 You don't lose any pixel data - lossless DNG compression is just Huffman coding (Huffman coding) - Wikipedia, the free encyclopedia. It just takes advantage of the fact that very often, a pixel has a similar value to the one next to it, so you can save space by just storing the difference between values. What you may see is some changes to metadata - Adobe tends to add their own - and you will probably lose the Leica MakerNotes, as they are tagged by Leica as "unsafe", and so should not be copied forward. However, that will happen regardless of whether you use lossless compression or not. Sandy Link to post Share on other sites More sharing options...
stunsworth Posted October 26, 2007 Share #4 Posted October 26, 2007 The clue is in the words 'lossless compression". The files are being compressed losslessly, a bit like them being zipped up. Nothing is lost. Link to post Share on other sites More sharing options...
asfeir Posted October 26, 2007 Author Share #5 Posted October 26, 2007 You don't lose any pixel data - lossless DNG compression is just Huffman coding (Huffman coding) - Wikipedia, the free encyclopedia. It just takes advantage of the fact that very often, a pixel has a similar value to the one next to it, so you can save space by just storing the difference between values. What you may see is some changes to metadata - Adobe tends to add their own - and you will probably lose the Leica MakerNotes, as they are tagged by Leica as "unsafe", and so should not be copied forward. However, that will happen regardless of whether you use lossless compression or not. Sandy I know what Huffman coding is, but could not find any reference to the type of compression. Thanks for pointing this out. This compression is very helpful to reduce the file size. I checked the metadata that is displayed in Lightroom. No changes take place there. Where can you see the Leica MakerNotes? Link to post Share on other sites More sharing options...
sandymc Posted October 26, 2007 Share #6 Posted October 26, 2007 Where can you see the Leica MakerNotes? You can't. Yet. But watch this space........ Sandy Link to post Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.