# Do you "Copy as DNG" when importing raw files into Lightroom?



## turnstyle (Jan 5, 2011)

Is there a conventional wisdom as to whether it's best to use "Copy as DNG" vs. just importing camera-specific raw files? It would be very helpful if you might add any advantages and/or disadvantages of converting to DNG, thanks!


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## Jim Wilde (Jan 5, 2011)

This is one of those issues which regularly divides the board, I've been a member for about a year and I've lost count of the number of times this question gets raised and hotly debated. In my opinion, there is no "right answer", merely a set of differing opinions about the merits of this feature (and the often associated question of creating XMP sidecar files). Here's the link to the last time we rode this particular merry-go-round - http://www.lightroomqueen.com/community/showthread.php?9981-Should-I-export-to-DNG - suggest you have a read and come back with any further questions. Plenty of people here ready to answer....


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## turnstyle (Jan 5, 2011)

Thanks for pointing me to that thread (I did actually search the forums before asking, but I searched on the wrong term).

I don't mean to raise the ire of johnbeardy (who was very helpful in the workflow thread) but I do think the "backup issue" would be a problem for me -- after many years of finger-crossing, I finally worked out a simple backup strategy that has worked very well for me. And changes to DNG files would trigger backups of the DNG files, and so I think (for me, for now) it makes more sense to stick to the camera-specific raw files, rather than convert them to DNG and also have to alter/complicate my backup strategy.

Question: assuming I do import camera-specific raw files (and do not "Copy as DNG") -- can Lightroom later "convert in place" those camera-specific raw files to DNGs?


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## johnbeardy (Jan 5, 2011)

I'll stay silent!


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## Jim Wilde (Jan 5, 2011)

turnstyle said:


> Thanks for pointing me to that thread (I did actually search the forums before asking, but I searched on the wrong term).
> 
> I don't mean to raise the ire of johnbeardy (who was very helpful in the workflow thread) but I do think the "backup issue" would be a problem for me -- after many years of finger-crossing, I finally worked out a simple backup strategy that has worked very well for me. And changes to DNG files would trigger backups of the DNG files, and so I think (for me, for now) it makes more sense to stick to the camera-specific raw files, rather than convert them to DNG and also have to alter/complicate my backup strategy.
> 
> Question: assuming I do import camera-specific raw files (and do not "Copy as DNG") -- can Lightroom later "convert in place" those camera-specific raw files to DNGs?



Don't be confused by the two separate issues: converting to DNG is one, writing metadata back into the DNG (or creating XMP sidecars in the case of Raw files) is the other. You do not have to do both! If you want to convert to DNG for some of the other reasons, that need not interfere with your backup strategy....it's only when you then decide to write XMP back into the file that it 'could' trigger backups. As I said, think it all through then make your decision.

John, I'm going to remember you said that!!


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## turnstyle (Jan 5, 2011)

I guess I actually have 2 questions:

1) Can Lightroom later "convert in place" camera-specific raw files to DNG? Meaning: if I stick to my camera-specific raw files for now, and process them in Lightroom, can I later easily convert the raws to DNGs keeping all the Lightroom process changes?

2) Can Lightroom be configured to not alter the DNG files? And, if so, is there still an advantage to using DNG over the camera-specific raw files? (ie, this takes the backup issue off the table.)


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## Jim Wilde (Jan 5, 2011)

1. Yes....select the picture(s) in the Library, then go to Library>Convert Photo to DNG. This is my own "Get out of Jail Free Card"....I don't convert to DNG, but I know I can at any time of my choosing in the future.

2. By default Lightroom does NOT alter the original files (Raw, DNG, whatever)....there is a Catalog setting (Edit>catalog Settings>Metadata tab) which will allow you to "Automatically write changes to XMP"....by default this option is NOT selected, so you would have to go turn it on if that's what you wanted. At any time you can select picture(s) and hit Ctrl+S to one-time write metadata into the files/sidecars.


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## MarkNicholas (Jan 5, 2011)

Just to open pandora's box a little wider should not the first question be " why would I even want to use DNG files over proprietary RAW files". No one has yet managed to provide me with a convincing reason to do so.


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## turnstyle (Jan 5, 2011)

So, if Lightroom doesn't alter DNG files by default, then the "backup issue" seems to be irrelevant.

In that case, what are the advantages/disadvantages to DNG? (most all threads seem to come back to the backup issue, which seems odd if Lightroom doesn't alter DNG by default)


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## Jim Wilde (Jan 5, 2011)

Please re-read the second post in that thread I referenced, where Victoria sets out several perceived advantages of DNG conversion. They may or may not be persuasive, depends on your own persepctive I guess. For me those reasons aren't compelling enough - yet - so I do not convert, though I can fully understand why others may feel the opposite.

This has all the makings of another spin on the merry-go-round, so I think I'll jump off now before it gets up to speed!


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## turnstyle (Jan 5, 2011)

Yes, I tend to see it as you do, TNG -- not quite enough benefit to make the jump (and, as you noted, we can convert to DNG later) -- I can also imagine some potential problems: for example, let's say there's a little bug in Lightroom's ability to read some camera-specific raw format. And Lightroom converts that raw file to DNG. In this case, that little bug seems like it would get permanently encoded into the DNG file. On the other hand, if you keep working with the original raw file, and the little bug later gets fixed in Lightroom, then it's no longer an issue, whereas it would remain in the DNG.


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## Denis de Gannes (Jan 5, 2011)

Adobe DNG Converter / Lightroom will only be able to convert a raw file to dng after they have provided support for the particular camera. As far I can see the primary reason for Adobe maintaining the DNG conversion process is to enable users of earlier versions of ACR to have a means of continuing to work with files from cameras manufactured after their version of the software. 

For instance users of cameras where support was only provided in LR 3.x/ACR 6.x can use the latest DNG converter to process their raw files and then have the ability to process the dng in LR 2.x/ ACR 5.x.


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## dj_paige (Jan 5, 2011)

Without getting into details, let me cast my vote for using the camera proprietary format and I don't convert to DNG.


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## clee01l (Jan 6, 2011)

dj_paige said:


> Without getting into details, let me cast my vote for using the camera proprietary format and I don't convert to DNG.


 
As usual, I cast my vote with Paige.  My camera writes DNGs in the camera, so the RAW files I import are already DNG. I see no need to keep and manage a second RAW master file.  If I ever buy a camera that only creates a proprietary RAW format like CR2 or NEF, That is what I'll import.  I'll miss the advantages of having a DNG file, but I won't convert my master to that format just to take advantage of it.


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## Mark Sirota (Jan 6, 2011)

I don't convert to DNG.  And I don't write XMP data to disk.

But there is one up-and-coming compelling case for DNG, at least for me -- data verification.  Effectively, a built-in detection mechanism for file corruption.

So far that hasn't been a powerful enough draw for me to convert, but it's on my radar.


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## dj_paige (Jan 6, 2011)

Ben, there shouldn't be any difference in the quality of the image (or the quality of your edits) between DNG and Raw. It seems like you are saying there is a quality difference. Could you explain further?


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## Replytoken (Jan 6, 2011)

I am with John and Victoria.  I keep my original NEF files, but work with converted DNG files in LR.  As I use ImageIngester to do the renaming and DNG conversion, in conjunction with Adobe's DNG Converter, I have ImageIngester verify the files as well during the process.

--Ken


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## RikkFlohr (Jan 6, 2011)

I backup CR2s as I convert to DNG on import. Upon the creation of the third back up  (1 Copy, 1 in Fireproof Safe, 1 offsite) I delete the CR2s. (60 days). By then I have generally verified no corruption or issues as I have handled each file multiple times and am usually archiving the particular job then. I have never gone to the backup cr2's so far. (fingers crossed)


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## sizzlingbadger (Jan 6, 2011)

I used to convert to DNG but don't anymore. It was pointless for me and I ended up using too much disk space backing up NEF files just in case....


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## b_gossweiler (Jan 6, 2011)

I don't convert to DNG, and I write XMP's automatically.

Beat


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## Denis de Gannes (Jan 6, 2011)

I do not convert to DNG nor write to XMP's , I depend on the catalog and backups to maintain my work. 

Some of the other raw conversion software that I use do not work with DNG's, and the xmp from LR are of no use outside of LR or PS.


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## Graeme Brown (Jan 7, 2011)

If I used DNG (and I don't, for all the reasons above) I would keep a copy of the original RAW, and make sure that was properly backed up. I've never had a corrupt RAW but I have had an entire folder of DNG files corrupted during my brief flirtation with the format. With the catalog also being backed up I then wouldn't be worried about the DNG files being backed up, so I wouldn't bother. But that would require two copies of the master file rather than one, which seems excessive. 

And anyway, as I say, I don't do DNG.


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## Deleted member 8190 (Jan 18, 2011)

I didn't know what XMP data was before yesterday, but I selected "write XMP data to file" as the default then did a manual save of it to all of my files. Not too much later, I needed to remove a few thousand files from the catalog and re-import them sort them into folders by date, and having the keywords and other info embedded in the files really saved the day.


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## BillBoaden (Feb 20, 2011)

I keep two completely separate folders. The import folder holds Camera RAW (Canon & Sony) and jpg photos in their own folders. I then import into another folder that Lightroom uses. This has a folder for DNG (converted on import) and another for jpg. I backup the import folder onto another hard disk. I use a Mac and therefore have Time Machine running to back things up as well. From time to time I use Super Duper to backup onto a third hard disk. I just like to keep the imported files untouched. I realise this may be wasteful of storage space but it is pretty cheap now.

Bill


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