TK! Posted November 14, 2015 Share #1 Posted November 14, 2015 Advertisement (gone after registration) Hi all, from one of the posts I learned the DNGs from the Q are uncompressed. I had a try zipping them (lossless) and I see a reduction of about 10% (I use bzip2). So I plan to zip all over my drive. My software "digikam" will simply ignore the "L10xxx.DNG.bz2"-files. I am fine with that. Good idea? - TK! Link to post Share on other sites More sharing options...
Advertisement Posted November 14, 2015 Posted November 14, 2015 Hi TK!, Take a look here Zipping the DNGs. I'm sure you'll find what you were looking for!
katsanes Posted November 14, 2015 Share #2 Posted November 14, 2015 I haven't done this, but I hear you can reduce the files by nearly half by using Lightroom to "Convert to DNG" as well. Link to post Share on other sites More sharing options...
CharlesL Posted November 15, 2015 Share #3 Posted November 15, 2015 I haven't done this, but I hear you can reduce the files by nearly half by using Lightroom to "Convert to DNG" as well. You can also use the free standalone program Adobe DNG Converter. I tried one file from a Leica Q. It went from 42 to 25 MB. I opened both in Raw Therapee. I could not see a difference looking at them and looking at their Raw Therapee histograms - but I wonder. Link to post Share on other sites More sharing options...
ricky1981 Posted November 16, 2015 Share #4 Posted November 16, 2015 I wouldn't zip them as you then need to unzip them each time in order to view/use the files, just use the options mention above or even convert to jpg once you've finished your PP work (assuming you are sure you won't want to use a different PP process later). Link to post Share on other sites More sharing options...
CheshireCat Posted November 16, 2015 Share #5 Posted November 16, 2015 from one of the posts I learned the DNGs from the Q are uncompressed. I had a try zipping them (lossless) and I see a reduction of about 10% (I use bzip2). So I plan to zip all over my drive. [...] Good idea? Not a good idea. I don't own a Q, but with my M9 all you needed to do is select all images in Lightroom and then "Update DNG Preview and Metadata". This will automatically (silently) apply the proper DNG lossless compression, which is much more efficient than bzip2 for image data. Wait for the process to complete, and check the files on disk. The average file size should now be 50% of the original. Link to post Share on other sites More sharing options...
marchyman Posted November 16, 2015 Share #6 Posted November 16, 2015 Thanks CheshireCat. That works with Q DNG files, too. Just tried it in a folder where the original DNG size was about 43 MB for half a dozen files. After "Update DNG Preview and Metadata" The size changed to 26 ~ 31 MB. Not half, but still a big drop. Link to post Share on other sites More sharing options...
katsanes Posted November 16, 2015 Share #7 Posted November 16, 2015 Advertisement (gone after registration) I just backed up a folder with 147 Leica DNG files in it and let Lightroom "Convert to DNG". Of the 147 files, the Leicas were consistently 43.1mb, the Lightroom versions ranged from 35.2 all the way down to 21.3mb. The median file size was 28.8mb for 147 files. EDIT: Also, that means the folder went from 6.34GB on disk to 4.12GB, so not an insignificant reduction! Link to post Share on other sites More sharing options...
ricky1981 Posted November 16, 2015 Share #8 Posted November 16, 2015 I'm pretty sure the Q writes uncompressed RAW files, I presume they did that because the time to compress them is more than the time saved in writing the smaller files to the buffer. Would be nice to have the option to use compressed RAW (compressed RAW files are still lossless AFAIK) but I think I'll be seeing flying bacon before that gets added! Link to post Share on other sites More sharing options...
katsanes Posted November 16, 2015 Share #9 Posted November 16, 2015 Is there any down side to using "lossless" compression on these files?? Is it really just shrinking the "white space" of the file and producing the exact same quality? Lossless indicates no downside, but I'm far from an expert! Link to post Share on other sites More sharing options...
CheshireCat Posted November 17, 2015 Share #10 Posted November 17, 2015 I'm pretty sure the Q writes uncompressed RAW files, I presume they did that because the time to compress them is more than the time saved in writing the smaller files to the buffer. No, it is actually because Leica/Panasonic engineers should know better. Link to post Share on other sites More sharing options...
CheshireCat Posted November 17, 2015 Share #11 Posted November 17, 2015 Is there any down side to using "lossless" compression on these files?? Is it really just shrinking the "white space" of the file and producing the exact same quality? Lossless indicates no downside, but I'm far from an expert! No downside. No worries. Link to post Share on other sites More sharing options...
pico Posted November 17, 2015 Share #12 Posted November 17, 2015 IMHO, zipping DNG files is a waste of time and resources, even if it is automated. Link to post Share on other sites More sharing options...
CheshireCat Posted November 17, 2015 Share #13 Posted November 17, 2015 IMHO, zipping DNG files is a waste of time and resources, even if it is automated. Yeah, we are past that Link to post Share on other sites More sharing options...
marchyman Posted November 17, 2015 Share #14 Posted November 17, 2015 Is there any down side to using "lossless" compression on these files?? Is it really just shrinking the "white space" of the file and producing the exact same quality? Lossless indicates no downside, but I'm far from an expert! One very minor downside. After complaining to Adobe about what I thought was a lightroom bug I found out that the actual error is with Leica metadata on the Q. This info came from some experts in the Lightroom forum. EXIF nerd stuff follows... Leica includes this bit of metadata: EXIF:MakerNoteSafety = Safe That tells software such as lightroom the the various blocks of metadata called Maker Notes are self contained and can be moved around as metadata is changed, added, or removed. However, one specific Maker Note generated by the Q is NOT self contained. The note contain absolute offsets to data inside the note. Since the offset isn't relative to the start of the note when the metadata is moved the offsets are incorrect. So what does that mean? After "Update DNG Preview and Metadata" the Leica metadata for "Original File Name", "Original Directory", "Original File Index", and Film Mode" (and maybe one other) are incorrect. If you don't use those metadata fields this isn't a big deal. I was going to use "Original File Index". Now I'll have to wait until Leica fixes this (I hope) in some future firmware release. I've reported the issue to Leica. Link to post Share on other sites More sharing options...
TK! Posted November 17, 2015 Author Share #15 Posted November 17, 2015 That's bad news. So never touch the DNGs... And yes, bzipping all the files does seem to be worth time & effort. Hm. - TK! Link to post Share on other sites More sharing options...
CheshireCat Posted November 17, 2015 Share #16 Posted November 17, 2015 That's bad news. So never touch the DNGs... And yes, bzipping all the files does seem to be worth time & effort. Hm. Sorry, but both sentences don't make any sense to me First, you should blame Leica for: 1) Not adding lossless-compressed DNG as an option on the Q. 2) Delivering again a firmware full of bugs. Second, I would definitely go ahead and modify the DNG files at the cost of those few lost [useless] metadata. Anyways, it's your choice... just note that if you don't "Update Preview and Metadata", all your development settings will *not* be saved in the DNG, so be sure to backup your Lightroom catalog [proprietary closed-source crap]. Link to post Share on other sites More sharing options...
jaapv Posted November 17, 2015 Share #17 Posted November 17, 2015 Why should one want to go to the trouble of zipping/compressing all this stuff, just to gain a few MBs, I mean, what does a four Terabyte disk cost nowadays? - Or cloud storage for that matter. Link to post Share on other sites More sharing options...
katsanes Posted November 17, 2015 Share #18 Posted November 17, 2015 Why should one want to go to the trouble of zipping/compressing all this stuff, just to gain a few MBs, I mean, what does a four Terabyte disk cost nowadays? - Or cloud storage for that matter. You're right, but laptops don't always have such huge drives (at least not locally). I offload older stuff to a NAS, but I like to keep my recent stuff 1-2 years back on my laptop and it does add up quick, especially since I have video content as well... Link to post Share on other sites More sharing options...
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