# Should I export to DNG



## pszilard (Sep 19, 2010)

I shoot Nikon Raw(NEF) + JPG files (or just raw) on my Nikons and "native" DNG on my Ricoh GX1''.

Should I use LR to create DNGs?

What are the benefits, and drawbacks? Any loss of data?
Thanks again...


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## Victoria Bampton (Sep 19, 2010)

Ah, that old chestnut!

Primary advantages: all encapsulated in one file with no sidecars to lose, you can update the preview to reflect your edits, file sizes are usually smaller, documented format should be around forever, compatibility with older ACR versions that don't support the camera, and the DNG Hash is up and coming as an early corruption warning.

Primary disadvantages: some people like sidecar files, and the manufacturer's software (i.e. Nikon's software) won't read DNG files.


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## pszilard (Sep 19, 2010)

Thanks Victoria. Sorry if this has been thrashed to death already 
Do YOU use DNGs?


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## Victoria Bampton (Sep 19, 2010)

LOL It's a popular debate everywhere. I'd usually point you to other old threads to get a few more viewpoints, but a lot of the archives are offline at the moment. There's a chunk in the book which goes into more detail on the pros and cons. 

Personally, yes, I do now for my working files - I like having the updated preview and I can see the DNG Hash becoming a bigger deal before too long. I'm a bit of a packrat, and my first copy off the card is backed up in the manufacturer's format offline before I convert to DNG, just in case I ever wanted to go back to use the manufacturer's software or something, but in 3 years, I've never pulled one of those files yet. I'm almost verging on the point of not bothering to keep the manufacturer's format now.

It's one of those questions that just doesn't have a right or wrong answer, and you'll find people who'll fight for both sides so those threads tend to get loooooong!


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## johnbeardy (Sep 19, 2010)

It might be worth searching back - there was a thread on this recently.

Anticipating your question, yes I do, but I keep my NEFs too, just in case of I'm not sure what. Essentially I process NEFs up to the point when I decide which images to keep and the images appear "done". At that point I create DNGs and archive the NEFs (never to be seen again?)

John


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## ukbrown (Sep 19, 2010)

After reading victoria's book I though I would give it a go to see if it suited me. It did. I use the copy as DNG and never see a raw file anymore.

Why, smaller files (15-2'%), faster processing becuase of smaller files (I think?). These were my reasons.


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## camerashy (Sep 19, 2010)

I'm just starting to use this workflow, save NEF's after importing from card then convert to DNG.
I have never had a consistent workflow but now look forward to having a routine.
Dave


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## Jim Wilde (Sep 19, 2010)

I'm in the other camp still. I doubt I'll ever find it in myself to delete my original RAW files (they are after all my originals), and all the "advantages" of converting to DNG are just not persuasive enough for me to do the conversion and retain the two formats. So unless some more powerful reason comes along (may be the DNG Hash that Victoria mentions) I guess I'll be sticking with RAW for the time being. I'm not unhappy at that prospect, though I do understand that others may see things differently.


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## pszilard (Sep 19, 2010)

As Victoria points out, the camera manufacturers do not release their raw file specs, and 3rd parties like Adobe have to reverse engineer the decoding. To me that says that there is always a possibility that recoding to DNG may loose some information. 

If I stay with raw as my originals then I'll always have the option to go back to the manufacturer's converter if I so wish. Or indeed to another 3rd party such as Bibble or Capture One, or DXO or Oloneo, etc.

So to mind mind, RAW is the safest option.


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## johnbeardy (Sep 19, 2010)

[quote author=TNG link=topic=11'72.msg74476#msg74476 date=1284931469]
I'm in the other camp still. I doubt I'll ever find it in myself to delete my original RAW files...
[/quote]
Using DNG doesn't mean deleting one's raw files. There are some who do, Peter Krogh for instance, but here both Victoria and I keep them, and I've been using DNG since well before LR was introduced.

John


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## Graeme Brown (Sep 19, 2010)

I flirted with DNG for a few months but I had problems with some files getting corrupted, and stupidly I didn't have the originals. The files were recoverable with a bit of effort, but for me I can't see any practical advantages of DNG so I'm sticking with Raw.


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## Jim Wilde (Sep 19, 2010)

[quote author=johnbeardy link=topic=11'72.msg7448'#msg7448' date=1284932613]
[quote author=TNG link=topic=11'72.msg74476#msg74476 date=1284931469]
I'm in the other camp still. I doubt I'll ever find it in myself to delete my original RAW files...
[/quote]
Using DNG doesn't mean deleting one's raw files. There are some who do, Peter Krogh for instance, but here both Victoria and I keep them, and I've been using DNG since well before LR was introduced.

John
[/quote]

I know that John, I was just trying to say that if I'm keeping the RAW file anyway, I can't then see the point of having BOTH the RAW and DNGs. It's just the way I see it, I guess....as I said there's no powerful argument (yet) for me to have both, though obviously some other people view things differently. 

If I was a pro, I might be tempted by the 'include updated metadata' argument....but I'm not, so I'm not.


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## Victoria Bampton (Sep 20, 2010)

[quote author=pszilard link=topic=11'72.msg74478#msg74478 date=1284932161]
As Victoria points out, the camera manufacturers do not release their raw file specs, and 3rd parties like Adobe have to reverse engineer the decoding. To me that says that there is always a possibility that recoding to DNG may loose some information. 
[/quote]

For Nikon & Canon, everything's transferred, even if they don't understand it, so no worries on that one.

You've done something most people don't - you've made an educated decision and you know why you've made that decision, rather than just taking other people's word for it, which is great to see.


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## pszilard (Sep 20, 2010)

[quote author=Victoria Bampton link=topic=11'72.msg745'4#msg745'4 date=1284963752]
For Nikon & Canon, everything's transferred, even if they don't understand it, so no worries on that one.
[/quote]

I've ran a comparison and the DNG file was about 1MB smaller than the losslesly compressed Nikon NEF file. Perhaps the DNG drops the Nikon's embedded JPG preview. Even so, assuming that 1''% of the Nikon raw data was encapsulated within the DNG file, I don't think that Nikon's raw converter would process the DNG file - which means that the user's bridges had been burned. Whereas staying with the original raw files, there is no such exposure.

Anyway,_ you pays your money and you takes your chance_, as they say.


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## Victoria Bampton (Sep 20, 2010)

The compression algorithm on DNG files is better, which results in the smaller file sizes. But yes, you're absolutely right, Nikon's software won't read DNG's, which is the primary con.


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## johnbeardy (Sep 20, 2010)

File size isn't a reason for switching, just a minor side effect. It's because of more optimised compression, *not* data loss, and it varies greatly between cameras. You can open DNGs in a range of other raw converters (eg Aperture, CaptureOne) but no-one here is advocating throwing away your raw files, just archiving them.


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## johnbeardy (Sep 20, 2010)

[quote author=Victoria Bampton link=topic=11'72.msg74518#msg74518 date=1284979466]
But yes ... Nikon's software won't read DNG's, which is the primary con.
[/quote]
Is that a con? It makes me wonder what kind of "con" we're talking about!


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## Victoria Bampton (Sep 20, 2010)

[quote author=johnbeardy link=topic=11'72.msg7452'#msg7452' date=12849799'6]
Is that a con? It makes me wonder what kind of "con" we're talking about! 
[/quote]

LOL Well, that one's in the eye of the beholder. I'm still wishing the manufacturers would stop being so stubborn, but I never use their software either.


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## ukbrown (Sep 20, 2010)

> File size isn't a reason for switching, just a minor side effect



I disagree as I think it makes for faster processing and means I need less hard disk space (for main storage, backup storage 1 and backup storage 3).

saving 5-6MB a picture to me was the main reason.


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## Mark Sirota (Sep 20, 2010)

[quote author=Victoria Bampton link=topic=11'72.msg74427#msg74427 date=12848873'8]
Primary disadvantages: some people like sidecar files, and the manufacturer's software (i.e. Nikon's software) won't read DNG files.[/quote]

One more "primary disadvantage", relating to backups:

If you take advantage of the DNG's embedded XMP data and updated previews, then your backups will be bigger and slower because you have to back up the whole thing each time it changes.

If you use proprietary raw files and write out XMP data, you only need to back up the sidecars which are far, far smaller.

If you don't write that stuff out (whether you use DNG or proprietary raw files), you don't have to back anything up in an ongoing fashion; your original files and folders are never touched so you can just duplicate them once after Import and you're done.


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## johnbeardy (Sep 20, 2010)

[quote author=Mark Sirota link=topic=11'72.msg74535#msg74535 date=1285''1749]
One more "primary disadvantage", relating to backups:
If you take advantage of the DNG's embedded XMP data and updated previews, then your backups will be bigger and slower because you have to back up the whole thing each time it changes.
[/quote]
You know, just because you write data back to your online or working DNGs does not mean they then need backing up again. One backs up the DNGs after they are created, and the catalogue regularly. This captures all your image data and all your work.

John


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## ukbrown (Sep 20, 2010)

I think you are quite right about backing up, trying to work out which files are new and which files have been writen to but don;t need backing up may stress out many backup products that see if a file has been updated since the last time it was backed up. I wouldn't trust myself to do it manually


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## johnbeardy (Sep 20, 2010)

I just keep new and existing DNGs on separate drives. Fresh DNGs are on a drive covered by backup, after which they go onto a drive that isn't backed up. However one does it, and that's pretty simple, there's no need to repeatedly back up your DNGs.


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## b_gossweiler (Sep 20, 2010)

For me, one of the major cons is the fact that a large DNG file is updated (and marked for backup) when you write back metadata.

As I never had any need to keep all in one file, I stay with my .cr2's.

Beat


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## ukbrown (Sep 20, 2010)

John, interested in this moving files around as it sounds like a good idea. What's involved in the lightroom side of it with re linking your catalog back to the pictures (in whatever format)


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## pszilard (Sep 19, 2010)

I shoot Nikon Raw(NEF) + JPG files (or just raw) on my Nikons and "native" DNG on my Ricoh GX1''.

Should I use LR to create DNGs?

What are the benefits, and drawbacks? Any loss of data?
Thanks again...


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## johnbeardy (Sep 20, 2010)

[quote author=b_gossweiler link=topic=11'72.msg74552#msg74552 date=1285'13'3']
For me, one of the major cons is the fact that a large DNG file is updated (and marked for backup) when you write back metadata.
[/quote]
At the risk of repeating myself, that's a problem with backup strategy - not a weakness of DNG.

[quote author=ukbrown link=topic=11'72.msg74555#msg74555 date=1285'14556]
John, interested in this moving files around as it sounds like a good idea. What's involved in the lightroom side of it with re linking your catalog back to the pictures (in whatever format)
[/quote]
All done in Lightroom - nothing more complicated than dragging a folder from one drive to another.

John


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## Graeme Brown (Sep 20, 2010)

[quote author=johnbeardy link=topic=11'72.msg74556#msg74556 date=1285'14856]
[quote author=b_gossweiler link=topic=11'72.msg74552#msg74552 date=1285'13'3']
For me, one of the major cons is the fact that a large DNG file is updated (and marked for backup) when you write back metadata.
[/quote]
At the risk of repeating myself, that's a problem with backup strategy - not a weakness of DNG.
[/quote]

I guess the point is that if you use RAW + XMP then updating a file will trigger a backup of a few tens of Kilobytes, whereas with DNG the whole file - tens of megabytes - is backed up. If your backup system keeps previous versions then pretty soon your archive is going to be huuuuuuge! That's one of the reasons I don't use DNG.


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## johnbeardy (Sep 20, 2010)

[quote author=Graeme Brown link=topic=11'72.msg74559#msg74559 date=1285'16443]
I guess the point is that if you use RAW + XMP then updating a file will trigger a backup of a few tens of Kilobytes, whereas with DNG the whole file - tens of megabytes - is backed up. If your backup system keeps previous versions then pretty soon your archive is going to be huuuuuuge! That's one of the reasons I don't use DNG.
[/quote]

No! That idea is only true if you've not thought through the backup strategy. I'm not sure how much clearer I can make this. 

And please let's get away from the idea that backing up your xmp files is a good backup. It misses a lot of your work. In a Lightroom context, XMP sidecars are for interchange with other apps - not backup.

John


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## Mark Sirota (Sep 20, 2010)

John, I agree that if you only use XMP data for interchange with other apps, then configuring your backup system to ignore the originals is a good strategy, provided you arrange for a one-time copy to other media after import -- whether or not you convert to DNG.


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## johnbeardy (Sep 20, 2010)

Mark, it's not a matter of "if you only use XMP data for interchange with other apps". What is the good of a backup that misses a lot of your Lightroom work? Thinking of XMP sidecars as backup is Bridge-era OldThink....


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## Victoria Bampton (Sep 20, 2010)

[quote author=pszilard link=topic=11'72.msg74435#msg74435 date=1284892829]
Sorry if this has been thrashed to death already 
[/quote]

Now you get the 'that old chestnut' comment Paul?!?


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## ukbrown (Sep 20, 2010)

> All done in Lightroom - nothing more complicated than dragging a folder from one drive to another.



Think this is something that I need to try, never really used LR for moving or even copying one or two files before, once imported always left them where they were.


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## pszilard (Sep 20, 2010)

LOL, have I opened a Pandora's box, or what!?

Actually it has become a very interesting thread. Another possible thought is that file accesses (aka rewrites) whenever I make any changes (which is every click of the mouse virtually), would perhaps be faster if they resulted in just updating XMP files rather than the entire DNG.

Hmm, I think I'll do some work now, instead. :icon_lol:


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## Mark Sirota (Sep 21, 2010)

John, I'm in complete agreement -- I don't write out XMP data at all, in fact. I think those who do, and consider it part of their backup strategy, are thinking (not incorrectly) that something is better than nothing, in the unlikely case that you can recover these backups but can't recover your catalog. I just don't think it's better enough to be worth the costs, for me.


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## b_gossweiler (Sep 21, 2010)

[quote author=johnbeardy link=topic=11'72.msg74556#msg74556 date=1285'14856]
[quote author=b_gossweiler link=topic=11'72.msg74552#msg74552 date=1285'13'3']
For me, one of the major cons is the fact that a large DNG file is updated (and marked for backup) when you write back metadata.
[/quote]
At the risk of repeating myself, that's a problem with backup strategy - not a weakness of DNG.
...
John
[/quote]

John, I don't agree with your statement. I'm not saying its a weakness of DNG, this is by design, and it's the same with JPGs or even databases. When you flip a bit in file, the file becomes eligible for a new backup.

_If_ people are using DNG's because they like to have it all in one file, the updated preview, the updated metadata, .... (and that's a good part of the reasoning pro DNG), then excluding those updates from backups by putting them onto a drive which is not backed up is not right. The idea of backups is that you have the most recent state possible of your data backed up, and not what you imported to begin with.

So you pay for having all in one file by having to back up this one (big) file when something changes.

"Change Bits" and "Last-Changed-Timestamps" have been and keep on being a very good technique for incremental backups in the entire industry.

Beat


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## Denis de Gannes (Sep 21, 2010)

My workflow with Lightroom is non DNG and non XMP. I just depend on my catalog for all my edits and back up regularly. That said I am not a pro so if I screw up, I go back to my raw files and re-edit. Thats what I do if I have to print a file that was originally done in LR 1 or 2, I redo in LR 3 and print. The previous edits are history, they are inferior anyway.


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## Victoria Bampton (Sep 21, 2010)

[quote author=pszilard link=topic=11'72.msg74572#msg74572 date=1285'2'646]Another possible thought is that file accesses (aka rewrites) whenever I make any changes (which is every click of the mouse virtually), would perhaps be faster if they resulted in just updating XMP files rather than the entire DNG.
[/quote]
Of course it's only ever writing back to the files if you have 'automatically write to xmp' turned on in preferences, and even then, there's a lag before it writes. The rest of the time your slider movements are just being written to the catalog, whatever file type you use.

And yes, it is Pandora's box!


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## johnbeardy (Sep 21, 2010)

[quote author=b_gossweiler link=topic=11'72.msg74576#msg74576 date=1285'2479']
John, I don't agree with your statement. I'm not saying its a weakness of DNG, this is by design, and it's the same with JPGs or even databases. When you flip a bit in file, the file becomes eligible for a new backup.
...The idea of backups is that you have the most recent state possible of your data backed up, and not what you imported to begin with.
[/quote]
No, it's that you can efficiently and completely restore your pictures and work to date. While DNG is designed to safely accept metadata changes, backups of changed DNGs are simply superfluous and as with XMP sidecars, that backup would only cover some of the Lightroom work done on them - so they aren't proper incremental backups anyway. All you need is the image data (those backups of freshly-created DNGs) and the catalogue telling your where your pictures should be, and recording your work on them.

Sorry if I've been a bit controversial and perhaps exasperated. But how many times in this thread has backup been cited as a reason for not using DNG? If you want to stick with raw, fine, but at least justify the decision on more solid grounds (such as wanting to use Nikon Capture or other raw converters that can't use DNG).

John


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## johnbeardy (Sep 21, 2010)

Pandora's soapbox?


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## MarkNicholas (Sep 21, 2010)

As I must have written on this forum many times I dislike DNG but love xmp. From the diverse responses it is clear that there is no correct or incorrect strategy. Its all down to personal preference. I think the only rule that applies is that you should regularly back-up your catalogue. Apart from that its down to your own personal preferences.


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## johnbeardy (Sep 21, 2010)

You don't think that's a "your mileage may vary" cop out? Basing one's views of DNG on shaky backup grounds isn't a matter of preference....


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## Victoria Bampton (Sep 21, 2010)

I think Paul's got the idea now guys....


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## Graeme Brown (Sep 21, 2010)

[quote author=b_gossweiler link=topic=11'72.msg74576#msg74576 date=1285'2479']
The idea of backups is that you have the most recent state possible of your data backed up, and not what you imported to begin with.
[/quote]


> No, it's that you can efficiently and completely restore your pictures and work to date.



Semantics aside, surely this is the same thing? The primary function of a backup is to enable you to keep working in the event of failure. An additional function may be to protect from inadvertent deletions or changes by holding a number of previous versions.



> While DNG is designed to safely accept metadata changes, backups of changed DNGs are simply superfluous and as with XMP sidecars, that backup would only cover some of the Lightroom work done on them - so they aren't proper incremental backups anyway.



I don't think anyone is arguing (and I certainly am not) to the contrary, and nobody is suggesting that only backing up XMP files is a sensible strategy. Having to exclude changed from backup DNG's while maintaining a backup of the original DNG's is just introducing unnecessary complication into the backup system, which is where errors can and will eventually occur.



> All you need is the image data (those backups of freshly-created DNGs) and the catalogue telling your where your pictures should be, and recording your work on them.



But the point remains surely that if you write the changes to the DNG it will trigger a large backup (relative to the equivalent RAW + XMP), and if you don't write the changes to DNG then you lose a lot of the point of DNG in the first place. You could have a set of 'master' DNG files (from your original import) and a set of 'working' DNG files, but that is creating even more data.



> Sorry if I've been a bit controversial and perhaps exasperated. But how many times in this thread has backup been cited as a reason for not using DNG?



Perhaps rather than being exasperated it would help if you outlined what you think is a valid backup strategy when using DNG? If you have already done so elsewhere I'd be interested to read it.


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## johnbeardy (Sep 21, 2010)

Graeme, I have already done so here - the DNG once only upon its creation, and then all subsequent work is covered by the catalogue backup. By physically separating new and already-backed-up DNGs, the backup routine is clearly-defined, and any changes written to "working" DNGs are to files on the drive that isn't covered by backup. If there's a crisis, restore the virgin DNGs from backup, restore the most recent catalogue, and I'm back to where I was. The changes written to the DNGs don't have quite as much backup value as people seem to think - after all, they don't include a lot of one's Lightroom work.

You also mention "the point of DNG in the first place". Thinking back to Victoria's first response, there are a number of points. She didn't really elaborate on why they mattered, but each is important in its own right.

John


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## Graeme Brown (Sep 21, 2010)

You're missing the point John, no-one is saying that having data encapsulated within the DNG is a form of backup any more than saying that XMP is a sufficient backup. XMP provides a degree of additional safety in the event of corruption of a catalog, but mostly it provides data to Bridge and other software. That's all.

I can see a number of disadvantages with your backup strategy:

1. You have two copies of each DNG - the original one and the modified one - in different locations. That's twice as much space used compared to one Raw file and an XMP

2. Two hard disks doubles your chance of a disk failure
3. If your two DNG's have the same name then there is the potential to delete or use the wrong one.

4. If your two DNG's have different names it makes it hard (depending on your renaming strategy) to link the original file and the modified file should you ever wish to go back to the original

Using one drive with Raw files, XMP files and the catlog files, which is fully backed up is a simpler scheme which uses less space and has none of the disadvantages listed above. If using DNG confers sufficient advantages to offset these points then fine, but in my opinion it does not therefore I am quite happy with Raw files. 

Victoria's list of the plus points of DNG is quite comprehensive, but for me personally they don't make a compelling argument. That's just my considered opinion as a working photographer with a background in IT, I'm not saying Victoria's wrong (I would never say that!).


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## Victoria Bampton (Sep 21, 2010)

[quote author=Graeme Brown link=topic=11'72.msg74629#msg74629 date=1285'74473]
Using one drive with Raw files, XMP files and the catlog files, which is fully backed up is a simpler scheme which uses less space and has none of the disadvantages listed above. 
[/quote]

In your backup system, what happens if your drive starts to go bad and you don't notice that your raw files are silently becoming corrupted, and because you haven't noticed, those corrupted files are then replicated to your backup?

(Oh, and you can say I'm wrong any time you like, as long as you give me a good reason! )


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## Victoria Bampton (Sep 21, 2010)

[quote author=johnbeardy link=topic=11'72.msg74628#msg74628 date=1285'72672]
Thinking back to Victoria's first response, there are a number of points. She didn't really elaborate on why they mattered, but each is important in its own right.
[/quote]

For anyone coming to this thread later, the more elaborate version of those points is at: http://www.lightroomqueen.com/lrqebook3-search/3'pages/lr3sample-'3-rawvsdng.pdf


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## johnbeardy (Sep 21, 2010)

On at least 3 cases here people have said the supposed backup requirement is precisely the reason....

Also please read what I said more carefully, and put to one side *your* assumption of my having "working" and "master" copies. I do not have the "two copies" you say in point 1, so your points 2-4 are no longer relevant. I have the one I referred to as "working". A working DNG is either on the new drive targeted by the backup, or it is on the drive which isn't. That's the same disc space as raw+xmp (actually, slightly less). 

Exasperated, and over and (definitively) out.

John


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## Graeme Brown (Sep 21, 2010)

[quote author=Victoria Bampton link=topic=11'72.msg74631#msg74631 date=1285'74896]
In your backup system, what happens if your drive starts to go bad and you don't notice that your raw files are silently becoming corrupted, and because you haven't noticed, those corrupted files are then replicated to your backup?[/quote]

If a file became corrupt I would use Time Machine to restore the original and if that failed (eg if the corruption had changed the file sufficiently to trigger TM to back it up again AND TM had deleted the original copy because it was out of space) then I would restore from the offsite backup of the original Raw file made when it was first shot and unmolested since. I'd then restore my catalog from a backup and have a cup of tea and a nice lie down.



> (Oh, and you can say I'm wrong any time you like, as long as you give me a good reason!  )



If it ever happens I'll let you know, but I'd have to be awfully sure. It would be a bit like going up to Paul McCartney and pushing him away from the piano saying "No you muppet, _Let it be_ goes like this ...."


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## Graeme Brown (Sep 21, 2010)

[quote author=johnbeardy link=topic=11'72.msg74633#msg74633 date=1285'75428]
On at least 3 cases here people have said the supposed backup requirement is precisely the reason....[/quote]

I didn't read anyone say that having XMP's means you don't need to backup the catalog, but anyway ....



> Also please read what I said more carefully, and put to one side *your* assumption of my having "working" and "master" copies. I do not have the "two copies" you say in point 1, so your points 2-4 are no longer relevant. I have the one I referred to as "working". A working DNG is either on the new drive targeted by the backup, or it is on the drive which isn't. That's the same disc space as raw+xmp (actually, slightly less).



So you have a new DNG which gets backed up, then the original is moved to another drive which is not backed up, is that correct? Presumably (as you've said there is only one copy) the original is deleted from the drive and only exists on the backup?

If I'm understanding that correctly then it makes a bit more sense, but the point remains that this separation is an additional step that only needs to be performed because you are using DNG, and your overall system of backups and files is still more complex than it would be with Raw files. As I said earlier you are also using twice as many drives which doubles the chances of a failure. 

As I said earlier, if the trade off is that you gain something from using DNG then great, but for me the equation doesn't balance.



> Exasperated, and over and (definitively) out.



Don't get exasperated, I'm just trying to understand a different way of working. I might even change my mind if the argument is sufficiently compelling!


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## pszilard (Sep 19, 2010)

I shoot Nikon Raw(NEF) + JPG files (or just raw) on my Nikons and "native" DNG on my Ricoh GX1''.

Should I use LR to create DNGs?

What are the benefits, and drawbacks? Any loss of data?
Thanks again...


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## johnbeardy (Sep 21, 2010)

I'll paraphrase you:

"So you have a new DNG which gets backed up, then the original is moved to another drive which is not backed up, is that correct? Presumably (as you've said there is only one copy) the original is deleted from the drive and only exists on the backup?"

I have a new DNG which gets backed up, then [n]it[/b] is moved to another drive which is not backed up. 

So in disc space terms, it's a wash and I have as many backups as with raw+xmp. Sure, moving is an additional step, but pretty trivial as I just drag and drop the folder in LR. I also say different drives, but it could be from one folder to another on the same drive.

You need to expand on Victoria's points to find the value. For instance, she mentions updating the embedded preview. Well, this preview can be used outside LR and I've used it in the past to ensure my previous cataloguing apps (Extensis Portfolio iView/Expression Media) displayed adjusted images. They output those embedded JPEGs infinitely faster than Lightroom, which goes back to the raw data (that's equally a fault of LR not being able to use previews as much as it should). So one can generate files for external printing, web, wedding DVD, or any other purposes. A client currently uses this aspect of DNG with one of his key clients that has insisted on getting copies of all originals. The images all need significant adjustment (they're stage shows), so sending them DNGs means the client sees and can print the properly-corrected image directly from their enterprise DAM (Picasa!) and offers some protection for his copyright.

To some extent, Lightroom has made me question whether I should continue with DNGs (I switched around the time CS2 came out) and I don't think Adobe have made it as much of a no-brainer as they might have done. The DNG hash is one example - Lightroom could use it to validate one's backup archive, for instance. On balance, I prefer it because I think metadata embedded in files is much better long term bet for the metadata I've taken the time to edit. Let's say that I'd received a well-deserved whack on the head and decided to move to Aperture, and that I'd stuck with raws and sidecars - until recently that would have meant losing my metadata (Ap v3 finally reads sidecars, even if a touch unreliably). That's still the same with CaptureOne - it'll preserve my DNG-based metadata though. Another example is in a thread here from someone trying to move from Expression Media - because he's using NEFs, he's unable to bring over his hierarchical keywords. My metadata's safely in my DNGs, so I'd always prefer embedded metadata.

A dog with a bone....

John


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## Graeme Brown (Sep 21, 2010)

[quote author=johnbeardy link=topic=11'72.msg74644#msg74644 date=1285'8'92']
I'll paraphrase you:

"So you have a new DNG which gets backed up, then the original is moved to another drive which is not backed up, is that correct? Presumably (as you've said there is only one copy) the original is deleted from the drive and only exists on the backup?"

I have a new DNG which gets backed up, then [n]it is moved to another drive which is not backed up. 

So in disc space terms, it's a wash and I have as many backups as with raw+xmp. [/quote]

Well no, actually, because according to a previous post you also have a copy of the raw file somewhere (as would be sensible). But disk space is cheap so it's not really an important issue at the end of the day




> Sure, moving is an additional step, but pretty trivial as I just drag and drop the folder in LR. I also say different drives, but it could be from one folder to another on the same drive.



Indeed



> You need to expand on Victoria's points to find the value. For instance, she mentions updating the embedded preview. Well, this preview can be used outside LR and I've used it in the past to ensure my previous cataloguing apps (Extensis Portfolio iView/Expression Media) displayed adjusted images. They output those embedded JPEGs infinitely faster than Lightroom, which goes back to the raw data (that's equally a fault of LR not being able to use previews as much as it should). So one can generate files for external printing, web, wedding DVD, or any other purposes. A client currently uses this aspect of DNG with one of his key clients that has insisted on getting copies of all originals. The images all need significant adjustment (they're stage shows), so sending them DNGs means the client sees and can print the properly-corrected image directly from their enterprise DAM (Picasa!) and offers some protection for his copyright.



Yes, but that's only relevant if you use those apps, which many don't - I'm Lightroom all the way (with an occasional side-order of Photoshop as necessary).



> To some extent, Lightroom has made me question whether I should continue with DNGs (I switched around the time CS2 came out) and I don't think Adobe have made it as much of a no-brainer as they might have done. The DNG hash is one example - Lightroom could use it to validate one's backup archive, for instance. On balance, I prefer it because I think metadata embedded in files is much better long term bet for the metadata I've taken the time to edit. Let's say that I'd received a well-deserved whack on the head and decided to move to Aperture, and that I'd stuck with raws and sidecars - until recently that would have meant losing my metadata (Ap v3 finally reads sidecars, even if a touch unreliably). That's still the same with CaptureOne - it'll preserve my DNG-based metadata though. Another example is in a thread here from someone trying to move from Expression Media - because he's using NEFs, he's unable to bring over his hierarchical keywords. My metadata's safely in my DNGs, so I'd always prefer embedded metadata.



The advantages all seem to relate to 3rd party apps, and there is no question that having open standard is a good thing, but for the majority of us there is no advantage in DNG and I'm of the "it ain't broke so don't try fixing it" school of thought. The futureproofing is an almost compelling reason, but it will be a long time until support for raw files is removed, and when it is I will convert everything in my archive to the then-current standard (which may be DNG or may be something else which has emerged).



> A dog with a bone....



Woof!


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## Replytoken (Sep 21, 2010)

I use a system similar to what John has described - NEF and corresponding DNG files are initially backed up and stored away from my working files before the working files are imported into LR. However, I do have a question about writing to DNG working files. In my current arrangement, so long as I keep my catalog backed up and my stored DNG files are OK, then John's method of recovery is quite simple. But, I was wondering about if one writes information to a working DNG. For example, if I write data to my working DNG files today (and back these files up), and then go about more work in LR on those files but do not write again to the DNG, but do back up my catalog, would my catalog and working files be out of sync if I needed to restore them? In other words, which DNG is LR looking for when I am restoring everything - the original DNG or the modified DNG? Or, does LR even care?

--Ken


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## b_gossweiler (Sep 21, 2010)

I would say, by now this has developed from a box to a mansion of Pandora  

Beat


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## Mark Sirota (Sep 21, 2010)

My fault. Sorry. I brought up the backups thing and unfortunately and incorrectly used the phrase "need to back up" regarding updated DNGs, which got John's hackles up. I've learned my lesson.


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## Victoria Bampton (Sep 21, 2010)

Some things don't change..... but I do love how polite everyone is here when putting their viewpoints, so great job everyone!

There is of course one other main benefit of DNG which I may have missed earlier in the thread... if you buy a new camera, but don't upgrade PS to a version that supports it, then DNG would allow PS to read the raw file whereas the proprietary raw would be ignored. If you always upgrade both LR and PS, or you don't buy new cameras, then that's not an issue for you, but it is an issue for some.

[quote author=Replytoken link=topic=11'72.msg74648#msg74648 date=1285'84958]In other words, which DNG is LR looking for when I am restoring everything - the original DNG or the modified DNG? Or, does LR even care?
[/quote]

Ken, Lr wouldn't care. It's a DNG file and all of the data is in the catalog, so you could easily write the data back out again.

[quote author=Graeme Brown link=topic=11'72.msg74636#msg74636 date=1285'77447]
If a file became corrupt I would use Time Machine to restore the original and if that failed (eg if the corruption had changed the file sufficiently to trigger TM to back it up again AND TM had deleted the original copy because it was out of space) then I would restore from the offsite backup of the original Raw file made when it was first shot and unmolested since. I'd then restore my catalog from a backup and have a cup of tea and a nice lie down.
[/quote]
Then you do basically the same as I do - an offsite backup of the original untouched, only my working and backup of working are DNG rather than CR2. As long as it's thought through, none of it's really a problem, whichever format you choose.


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## Replytoken (Sep 22, 2010)

[quote author=Victoria Bampton link=topic=11'72.msg74682#msg74682 date=12851'3'36]

[quote author=Replytoken link=topic=11'72.msg74648#msg74648 date=1285'84958]In other words, which DNG is LR looking for when I am restoring everything - the original DNG or the modified DNG? Or, does LR even care?
[/quote]

Ken, Lr wouldn't care. It's a DNG file and all of the data is in the catalog, so you could easily write the data back out again.

[/quote]

Thank you for the reply, Victoria. So LR does not care if any XML information has been previsouly written to the DNG file? It just looks at the "baseline" information in the DNG and takes over from there?

--Ken


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## Victoria Bampton (Sep 22, 2010)

Yes, it always assumes that its own database is correct for all metadata, unless you tell it otherwise.


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## wblink (Oct 4, 2010)

[quote author=Victoria Bampton link=topic=11'72.msg74524#msg74524 date=1284982721]
LOL Well, that one's in the eye of the beholder. I'm still wishing the manufacturers would stop being so stubborn, but I never use their software either.
[/quote]

Well,

For Nikon: CNX is produced by NIK which has many plugins for LR. Suppose they KNOW what they are doing.


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## johnbeardy (Oct 4, 2010)

Really? Apart from CNX's horrid UI and workflow, Nikon's SDK has a long and respectable history of corrupting NEF files, and even the infamous WB encryption wasn't completely deliberate.


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## sizzlingbadger (Oct 6, 2010)

The DNG backup (non)issue is often cited due to the limitations of the backup software. I use Time Machine and it will backup the dng file if it is altered in any way. I could exclude my folder from the backup but then new files that I import would not get backed up. So I use NEF's and XMP so that only the xmp file requires the backup. This is not my main reason for not using DNG, if really wanted to use DNG I would find a solution to the backup issue.

I like to be able to use other RAW converters from time to time and the NEF is far better supported. Even the products that do support DNG don't always render the image properly in my experience. Aperture and Capture One are both examples of this.


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## Dumbletore (Dec 4, 2010)

I have converted all RAWs to DG for some years now.
I now realize i am very annoyed by the fact that only few media players support the format.
I am not a professional photographer, so i have alotta private photos that i want to share with family and friends in the livingroom.
I stream with a NAS, watcing mediafiles with a media player connected to my TV.
It is impossible to view DNGs on the TV..
I even spoke to a ADOBE guy on a CS5 seminar - all he could suggest was connect a PC to the TV.

Hey - thats not the kind a adwise you are looking for. I really thought it was only because I was too stupid to know better..

Come on adobe. Improve that, or loose the support of private people..


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## Mark Sirota (Dec 4, 2010)

Dumbletore, welcome to Lightroom Forums.

Your TV would also probably be unable to display raw files, so the ability to play via NAS on your TV has no impact one way or the other. It can probably only display JPEGs.


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## Dumbletore (Dec 4, 2010)

Thats true, but still dissapointing, and i keep looking for a replacement for DNG.
BTW my media player supports jpg, bmp, gif, png, jpeg2''', jp2.

Does anybody like to tell their wife that if they want to see the recent photos on the TV, then bring a laptop to the pc?


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## Bruce J (Dec 7, 2010)

My solution to the problem is to export nearly all of my images in jpeg format to a NAS that the wife has access to.  She can view them any way she wants, email them, etc.  She never messes w/ the originals.  Takes a bit more storage space and processing time, but it keeps us both happy.  YMMV


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## Mark Sirota (Dec 7, 2010)

Consider using a Hard Drive Publish Collection instead of exporting.  Much easier to maintain.  Make it a Smart Collection and you can filter on a keyword, copy name, color label, etc. to auto-populate the ones you want to be made visible this way.


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## Jim Wilde (Dec 7, 2010)

Mark Sirota said:


> Consider using a Hard Drive Publish Collection instead of exporting.  Much easier to maintain.  Make it a Smart Collection and you can filter on a keyword, copy name, color label, etc. to auto-populate the ones you want to be made visible this way.


 
This is what I have recently started doing and it's great, especially using the Published Smart Folders....now if I can just get Lightroom to automatically indicate that there are new pictures waiting to be published, that would be even better. As it is at the moment I have to open each of my Hard Drive services (and my Flickr sets) in turn to see if a 'Publish' is needed. Is there something I'm missing, Mark?


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