7 Replies Latest reply on Feb 15, 2016 12:33 PM by cpgilles

    DNG vs Proprietary RAW file sizes

    cpgilles Level 1

      I was told that dng files are compressed lossless files and would be physically smaller than proprietary raw files and started using them in my workflow.  And that seems to be true with most Canon CR2 raw files.  However I have discovered a camera where that is not true and am looking for confirmation and an answer as to why.  I have both a Canon 5D Mark III and a Canon 5DS camera.  On the Canon 5D Mark III the dng files are all smaller than the corresponding CR2 raw file.  Roughly 17% smaller.  However on the 5DS the dng files are as much as 50% larger depending on the raw settings.  The 5DS is a 50mp camera.  Set at the maximum 50 mp the dng file is smaller.  On the smallest setting, 12 mp, the file sizes are about the same.  On the medium setting 28mp the files sizes can be 50% larger.  Anyone know why?  28 mp is the setting I use most of the time.