# Should I convert Nikon raw NEFs to DNG on import? And should I convert existing NEFs to DNGs?



## tonyoz (Sep 18, 2021)

Hi Forum gurus
I'm an amateur and have been importing a lot of Nikon NEFs over the years (various bodies) and for that matter RAW files from Canons, Lumix etc. Have done numerous edits, flags etc.
I have only now become aware of DNG.
I'm not sure what DNGs claimed benefits are, as of Sep 2021.
A. Are LRQ forumers in favor of DNG adoption?
B. Do you import into LrC using LrC or Bridge/orRaw?
C. And if I go foward with DNG is the process safe to convert my 10 years of existing RAWs to DNGs - will it proceed smoothly and integrate the edits and edit history and 'undo edit workback' options?

I'm asking because LrQ is ever-evolving and thought it would be good to have the latest experience

Thanks in anticipation


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## clee01l (Sep 18, 2021)

You will get answers the fall on both sides of the question.
In the for DNG conversion, the pluses are:
1. Built in Checksum So they you can tell if the DNG file has gone bad.
2. A marginally smaller file than the NEF 
3. DNG are a public format and all apps should be able to handle the DNG format. But thee same apps also handle the NEFs 

In favor of retaining the NEF. 
1. It is the original file and Nikon may develop future technology to improve the images based upon the content of the data stored in the Nikon file header.
I would recommend always keeping the NEF for future proofing.
To that end it seems pointless to create a RAW DNG that contains the RAW contents of the NEF if you are going to keep the NEF. 
2. Disk storage is relatively inexpensive so it matters little it you simply convert to DNG for smaller files. 
3. Checksums tell you that the contented of the file have degraded. Opening the file to discover that it can’t be read because of bit rot achieves the same end result as a Checksum tally. The real solution is to have sufficient file backups to recover.

I am on the side to preserve the NEF. Converting to DNG only slows the import process and adds additional overhead. 
Lightroom reads your NEF the same as it reads your DNG. Lightroom will always be able to read your NEF format so there is no worry that the NEF will somehow become obsolete.

I see DNGs as a useful RAW file format and given the opportunity to write DNGs in the camera as some dozen manufacturers already do would be optimum. I see no reason to convert to DNF as long as Lightroom is able to read the RAW NEF.


Sent from my iPad using Tapatalk


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## Linwood Ferguson (Sep 18, 2021)

What he said.    

For most people DNG's are a solution in search of a problem.  Make sure you are solving a problem before introducing more complexity and/or conversions of your images.

They are not a BAD thing.  They just don't solve a problem I have.


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## Conrad Chavez (Sep 18, 2021)

DNG could simplify things greatly if cameras saved directly to it, as some do but not most.
Although we have the option of converting proprietary raw files to DNG, most of the time the benefits don’t outweigh the drawbacks plus the time and trouble involved to convert thousands of images.
As long as software companies keep adding raw support for the latest cameras and don’t drop support for old ones, it’s hard to justify converting to DNG.

Where DNG has realized more of its original promise is in mobile phone OSs that added raw support for smartphone cameras. Apple ProRAW actually uses DNG, and my understanding is that Android phones save raw photos in DNG too. So we have all these raw files from a wide range of mobile devices that shoot raw straight to editor-ready, future-proof DNG with no conversion needed. Mobile photography achieved the vision of DNG that was never realized with regular cameras, where most camera makers still insist on saving raw to proprietary formats and not offering a DNG option.



tonyoz said:


> C. And if I go foward with DNG is the process safe to convert my 10 years of existing RAWs to DNGs - will it proceed smoothly and integrate the edits and edit history and 'undo edit workback' options?


If you select a raw file in Lightroom Classic and choose Library > Convert Photo to DNG, the new DNG takes the place of the original and carries forward the metadata of the replaced file, so you don’t lose metadata and history.


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## Roelof Moorlag (Sep 18, 2021)

tonyoz said:


> I'm not sure what DNGs claimed benefits are


This is a great resource for more information about DNG: DNG | dpBestflow

My main reason for an DNG central worfkflow is the build-in validation option for it in Lightroom.


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## Linwood Ferguson (Sep 18, 2021)

There is a  subtle aspect of DNG that can affect some users.  If you write metadata to files (either as a backup, or because certain tool operations may require it like capture time update, or interacting with external programs), with raw data it writes to an XMP "sidecar" file, which is a tiny text file of the same name and type XMP.   If you have a DNG, it writes it to the file itself. 

For some having one file rather than two is a benefit, but if you use cloud backup software (not Adobe cloud, but some other offline backup) this means with every update it copies the whole file, not just a piece.  So if you update the file 5 times in a month, 5 copies get uploaded.  With Raw, only 1 copy is updated then 4 uploads of the tiny XMP. 

This can also happen if you update the embedded preview, or make other changes that DNG allows but raw never does.

This is only a problem if it's a problem for y our backup scheme and space and upload speed.   

It also may be a philosophical issue -- personally I like that raw files are (almost) never changed.  Rewriting data is an opportunity for the system (whether due to software bugs or hardware) to screw up the data.  But all this stuff is VERY low probability problems so it is mostly a subjective matter.  The math is really in favor of the whole issue being moot. 

The protection against "bit rot" (google it) that Roelof mentioned is one of the strongest arguments in my mind for using it. However I think everyone's backup processes should incorporate a bit-rot protection of some sort anyway (but probably 99% of them do not, so kudos to DNG).   I.e. not just your images, but your financial records, family documents, etc.  Photographers we may be but there's a bit more to our computer data than photos.


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## clee01l (Sep 18, 2021)

I think it is wrong to say that "DNG protects against bit rot".   All the checksum does is make bit rot easier to identify.


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## Linwood Ferguson (Sep 18, 2021)

Fair enough, it's detection not prevention.  Backups are protection, but useless if  you don't know you lost something.


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## Kierphoto (Sep 18, 2021)

Attach your BackUp Hard disk to your computer
In LrCl select “Copy as DNG” and your normal destination. (I only have ONE Folder “(Name)Pictures” with many subfolders containing ALL my inported pictures/jobs) Your whole computer is in fact one HD so why spread it out on your Desktop.
Under “File Handling to the right select “Make a Second Copy To” - and select  your attached BackUp HardDisk.
It will allways be your original NEF or native files going to the attached backup HD When Importing.


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## Hal P Anderson (Sep 18, 2021)

Kierphoto said:


> Under “File Handling to the right select “Make a Second Copy To” - and select your attached BackUp HardDisk.


This doesn't create a backup that is at all easily usable. The directory structure doesn't match the structure that is maintained by Lightroom. Trying to restore your image library from that structure would be a total nightmare.

The "Make a Second Copy To" feature is to let you have two copies of your image files until your regular backup program runs and copies the LR images to your real backup disk. After that, you can (and probably should) delete the Second Copies.


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## Paul_DS256 (Sep 19, 2021)

To me, the option to convert to DNG is more Adobe promoting the DNG standard than adding any real benefit.


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## Kierphoto (Sep 19, 2021)

Hal P Anderson said:


> This doesn't create a backup that is at all easily usable. The directory structure doesn't match the structure that is maintained by Lightroom. Trying to restore your image library from that structure would be a total nightmare.
> 
> The "Make a Second Copy To" feature is to let you have two copies of your image files until your regular backup program runs and copies the LR images to your real backup disk. After that, you can (and probably should) delete the Second Copies.


No, it is quite easy.
Lightroom Classic is a quite simple program. The whole secret is to keep your Catalog. (Adjustments, Keywords etc) containing your Previews.
If you really have lost your Picture folder (”name”Pictures) you choose the BackupHD.
Choose IMPORT.  Find your BackUp HD and Folder.
Select copy as DNG/Copy (Uncheck “Don´t import Suspected Duplicates”) - and you will see that all missing files have enlighed Previews.
Then just Import - and your Preview and files are updated. (Even if you original was imported as DNG, the same adjustent are on your NEFs)

The “Make a Second Copy To” are for those who want an extra backup, to use in extreme cases.
Normally you just make a backup of your Catalog and your (“Name”Pictures folder)


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## Kierphoto (Sep 19, 2021)

If ALL  pictures are reimported:
In the above action you will have two identical previews. (One with “!”) in Grid View
In Library - Find all missing Photos.
Edit - Select All.
Photo - Remove Photos

Or deleted selcted Missing Photos.

Be careful what you delete.


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## Hal P Anderson (Sep 19, 2021)

Kierphoto said:


> Choose IMPORT. Find your BackUp HD and Folder.



You _*really *_don't want to re-import. That loses all your edits and metadata changes. Just copy your images from a proper backup to a fresh hard drive and point LR to those images.

What I said above was that the second copy on import is no kind of backup. If you are counting on them as a backup, you'll rue the day you actually have to use them.


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## Johan Elzenga (Sep 20, 2021)

I have to agree with Hal. Reimporting photos means you will lose all your work, unless you made a backup by using ‘Export as Original’ and so you included sidecar files with you backup. But even then you will lose some work, because not everything is written to sidecar files. If you do not have sidecar files in your backup, then the photos will come in as brand new, without any edits or added metadata. That is the worst possible solution and it is totally unnecessary. Lightooom knows where the photos are supposed to be, so just use your backup to restore them in that location and Lightroom will never know what happened.


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## Kierphoto (Sep 20, 2021)

Quite strange. It works fine for me. (Original import was in DNG)
Reimporting from BackUp HD in DNG as described above, automatically moves the old adjustment to the new imported file, with the dialog as shown in framegrap.
Maybee we are back to the original question in this thread. DNG versus NEF.
That adjustment are contained i DNG while NEF will give an .xmp.


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## Linwood Ferguson (Sep 20, 2021)

Whether you lose your adjustments depends on if you have the write-metadata setting enabled to automatically (and continually) write metadata to the files, which would be the DNG or the XMP.   However, it will write only to the catalog version, not any backup you made on import (we are mixing up some subject matter in there somewhere).


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## PhilBurton (Sep 20, 2021)

clee01l said:


> I see DNGs as a useful RAW file format and given the opportunity to write DNGs in the camera as some dozen manufacturers already do would be optimum. I see no reason to convert to DNF as long as Lightroom is able to read the RAW NEF.
> 
> 
> Sent from my iPad using Tapatalk


Every so often someone makes the argument that a future version of LR (or some other RAW editor) will no longer support NEFs.  While that argument might be valid for a minor market share, it makes no sense for Nikon, Canon, or Sony.

In the ever changing world of software, anything is theoretically possible.  But Lightroom dropping NEF support, not very likely.


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## Linwood Ferguson (Sep 20, 2021)

PhilBurton said:


> Every so often someone makes the argument that a future version of LR (or some other RAW editor) will no longer support NEFs.  While that argument might be valid for a minor market share, it makes no sense for Nikon, Canon, or Sony.
> 
> In the ever changing world of software, anything is theoretically possible.  But Lightroom dropping NEF support, not very likely.


I think it's also a moot argument for another reason -- it won't happen without notice (or a chance to notice).  Since DNG conversion is an automated process, just computer time, if I know I have an end-of-support for NEF's, I can convert then.

The argument would only apply if one somehow suddenly woke up in a world where there's no old version of LR to use to do the conversion, so I think only applies to those planning to time travel (well, at an accelerated rate -- we all time travel I guess, forward, 1x)


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## Conrad Chavez (Sep 20, 2021)

PhilBurton said:


> In the ever changing world of software, anything is theoretically possible.  But Lightroom dropping NEF support, not very likely.


Although let’s keep in mind that the question is not really about dropping support for "NEF" or "CRW" or… because those are not a single blanket format. NEF is the filename extension given to a very long list of individual and different camera (and even old Nikon scanning software) formats. What this is about is whether the earliest specific _camera models_ get dropped. Just like Victoria says in her article:
Should I convert to DNG?


> Some of Kodak’s early digital formats are already unsupported by Kodak themselves, so how long will it be before other formats start to go the same way? It may not be an issue at the moment, but do you want to have to keep checking your old file formats to make sure they’re still supported?


Of course this is not a short-term problem. Lightroom really is unlikely to drop support for the oldest Canon, Nikon, and Sony cameras any time soon. And they do, we’re probably going to get notice well in advance, plenty of time of convert to DNG if we want.

The following is my own speculation, but it could play out like this: Adobe starts deciding that the list of hundreds of supported cameras is getting too long, and cameras more than X years old are too large of a proportion of the download. (The Adobe Camera Raw installer is already over half a gigabyte; only 1/3 of that is the plug-in itself, all the rest is camera support). I would guess that they don't remove support completely, but would first take some camera support out of the core download (like the oldest NEF/CRW/ARW variants or least used other models) and make you download them on demand if you happen to own one of those models. Then later they could decide to drop support for some old cameras entirely, but it will be many years before that is likely.



Paul_DS256 said:


> To me, the option to convert to DNG is more Adobe promoting the DNG standard than adding any real benefit.


Well, they should promote DNG. If camera makers never implement DNG as a built-in save format out of camera, then all software companies must continue, in perpetuity, to reverse engineer the sensors of all cameras that are released, and over time the list of cameras to support grows from hundreds to thousands. This is an ongoing cost and time burden that is not equitable. A large company like Adobe has the resources to keep doing it, but the burden is proportionally higher on small software companies who maybe would like to apply raw support resources to something else. Although it is not so bad for software that gets raw support for new cameras from a source like macOS or open source raw decoder libraries instead of doing it themselves.

But thinking about it some more, even if cameras saved to DNG and simplified the lives of many software developers, Adobe would still choose to spend resources supporting new gear. Because Adobe also creates and provides camera raw profiles (e.g. Adobe Landscape, Camera Neutral…) tuned to each camera, and lens profiles, and DNG doesn’t remove the need to do that work.


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## Johan Elzenga (Sep 21, 2021)

Kierphoto said:


> Quite strange. It works fine for me. (Original import was in DNG)
> Reimporting from BackUp HD in DNG as described above, automatically moves the old adjustment to the new imported file, with the dialog as shown in framegrap.
> Maybee we are back to the original question in this thread. DNG versus NEF.
> That adjustment are contained i DNG while NEF will give an .xmp.


In that case, you had ‘Automatically write changes to XMP’ enabled, and regularly backed up the images again, so the updated XMP was backed up too. Lucky you. Many people would not think about backing up images if they did not add any images, so their backup may easily not contain the latest edits.

Even in this situation reimporting is not the best way to restore images however. Like I said before, not everything is written to XMP, so you will still lose quite a few things. You will lose virtual copies (which also means books, soft proofs), stacks, picks, collection memberships and publishing service membership. And anything else I may have forgotten.


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## Denis Pagé (Sep 27, 2021)

> Johan Elzenga said:
> 
> 
> > Even in this situation reimporting is not the best way to restore images however. Like I said before, not everything is written to XMP, so you will still lose quite a few things. You will lose virtual copies (which also means books, soft proofs), stacks, picks, collection memberships and publishing service membership. And anything else I may have forgotten.


Hi Johan,

This is the very exact and definitive reason why I stopped wondering on this subject. Seem it now make years we are discussing this but it is always nice to remember


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## kdlawler (Sep 27, 2021)

tonyoz said:


> Hi Forum gurus
> I'm an amateur and have been importing a lot of Nikon NEFs over the years (various bodies) and for that matter RAW files from Canons, Lumix etc. Have done numerous edits, flags etc.
> I have only now become aware of DNG.
> I'm not sure what DNGs claimed benefits are, as of Sep 2021.
> ...


I have been converting to DNGs since I started.  I ran into one weird situation where it was a problem.  I was considering entering an image into a contest and they wanted to see my finished JPG file plus the original out-of-camera raw, or NEF.  The rules stated that they wanted to include only images that hadn't been over-manipulated, thus requesting the NEF.  I've only seen that once.


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## Kirsty (Sep 30, 2021)

kdlawler said:


> I have been converting to DNGs since I started.  I ran into one weird situation where it was a problem.  I was considering entering an image into a contest and they wanted to see my finished JPG file plus the original out-of-camera raw, or NEF.  The rules stated that they wanted to include only images that hadn't been over-manipulated, thus requesting the NEF.  I've only seen that once.


I was going to mention this - specifically for any wildlife competitions which quite often ask (or can ask) for the original raw file.
I used to convert everything to DNG but have stopped doing it in order to retain the raw file format.


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## Jim Wilde (Sep 30, 2021)

Kirsty said:


> I used to convert everything to DNG but have stopped doing it in order to retain the raw file format.


Converting a raw file to DNG *does* retain the raw file format, i.e. the raw data is not changed in any way, so it should be acceptable to the people running the competition.


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## tonyoz (Sep 18, 2021)

Hi Forum gurus
I'm an amateur and have been importing a lot of Nikon NEFs over the years (various bodies) and for that matter RAW files from Canons, Lumix etc. Have done numerous edits, flags etc.
I have only now become aware of DNG.
I'm not sure what DNGs claimed benefits are, as of Sep 2021.
A. Are LRQ forumers in favor of DNG adoption?
B. Do you import into LrC using LrC or Bridge/orRaw?
C. And if I go foward with DNG is the process safe to convert my 10 years of existing RAWs to DNGs - will it proceed smoothly and integrate the edits and edit history and 'undo edit workback' options?

I'm asking because LrQ is ever-evolving and thought it would be good to have the latest experience

Thanks in anticipation


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## Denis de Gannes (Sep 30, 2021)

Jim Wilde said:


> Converting a raw file to DNG *does* retain the raw file format, i.e. the raw data is not changed in any way, so it should be acceptable to the people running the competition.


This may be true with the Adobe DNG converter and LrC doing the conversion, what about other applications like DxO and others?
DNG files could also contain tiff, jpeg and some other files.


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## Kirsty (Sep 30, 2021)

Jim Wilde said:


> Converting a raw file to DNG *does* retain the raw file format, i.e. the raw data is not changed in any way, so it should be acceptable to the people running the competition.


Unfortunately not… competitions like “the British wildlife photography awards” and many others wildlife comps will not accept a dng unless it is the native camera format.  That’s specifically stayed in the rules, so always best to check.


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## Jim Wilde (Sep 30, 2021)

Denis de Gannes said:


> This may be true with the Adobe DNG converter and LrC doing the conversion, what about other applications like DxO and others?
> DNG files could also contain tiff, jpeg and some other files.


Absolutely some DNG files will not contain raw data....but if a competition demands a raw file that means they have the ability to convert that raw data, so they should also have the means to determine if the presented DNG contains raw data or not. Maybe it's just too much trouble for them to do the validation.


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## clee01l (Sep 30, 2021)

Jim Wilde said:


> Converting a raw file to DNG *does* retain the raw file format, i.e. the raw data is not changed in any way, so it should be acceptable to the people running the competition.


While DNG is or can be a RAW file format, I would check with the people running the competition  before submitting.  Some competitions are reluctant to accept anything but an un adjusted SOC JPEG  and seem to be unaware that cameras being with RAW non RGB data.


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## Johan Elzenga (Sep 30, 2021)

Photo competitions do not normally ask for raw files from the start, but some of them ask potential winners to submit the raw file to check that the image has not been altered in ways not allowed in the rules. I agree with Jim that they should have to possibility to check whether a DNG contains raw data or not, but that may not be that easy. Panorama and hdr files created by Lightroom superficially look like raw files too, and HeliconFocus can do the same with a focus stack. So indeed they do not want to go through all that trouble and ask for proprietary raw. It is interesting to see what they do with cameras that can shoot both proprietary raw as well as dng…


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