How do I prevent LR from writing changes into DNG files? I don't want any changes whatsoever to my raw files. They should be kept as when imported from the camera.
Does your camera save the file as DNG.? If so then you should never save metadata to the file to prevent any changes. If your camera doesn't save DNG than you shouldn't be converting to DNG.
My cameras has the option to save as .dng, but how do I prevent LR to save changes to the .dng file when editing? Is the only solution to use proprietary raw format?
By default, Lightroom never writes to RAW or DNG files. You can turn on options to write to DNG files, or you can manually tell Lightroom write to DNG files. So, don't turn on that option and don't manually tell Lightroom to write to your DNG files. (Yes, I know there's no guarantee that you won't do it by mistake ... )
Another factor is to have pristine backups of your original DNGs. Then, even if you accidentally write to the DNG file by mistake, you still have an un-touched DNG file to use.
So where do I turn off writing to dng files?
Some cameras do offer that choice internally - for example, certain Pentax models allow either PEF or DNG format to be created, when set to Raw. PEF participates in a workflow where the writing of metadata by LrC or by ACR, happens as separate XMP sidecar files (which I prefer). However some camera models only offer DNG when set to Raw. In that case, to my knowledge your only choices are either opting to not write out any metadata updates at all - which is fine BTW - or else, to accept that it will be into the file header of the DNG that these metadata updates will get written with all that entails.
A further option is that while importing to LrC, you can set an alternative location where an independent copy of each imported file will get immediately put in dated folders, and not be itself imported at all, nor undergo any renaming nor default processing etc. That untouched "record copy" can later act as a fallback, in case something unwanted might happen to your imported file - though I have never had anything happen to LrC's source files, that could not be recovered from with the aid of standard periodic file backup, just to put this in IMO due proportion.
Obviously this alternative location would need lots of capacity, plus you would still want to backup all the main working folders, as well as the Catalog and such, anyway.
Yes, non-DNG propriatary RAW files are the only format that doesn't save to the RAW except if you tell Lightroom to change the capture date and then save the metadata. Then only the capture date is changed.
Like DJ said, make backups of you photos immediately. Preferably make multiple backups. I have 2 local backup drives, one offsite backup drive and most photos (keepers) backed up in the cloud (not Adobe Cloud)
The stupidity of writing into dng files is among other things that backup software will see the file as altered whenever you edit it, and therefore will include it in the next backup, causing backups slow and huge. If dng files were left untouched, they would only need to be backuped once.
What type of changes are you referring to?
Quote " What type of changes are you referring to?"
I am not certain specifically what your question refers to but would just offer the following comment.
Lightroom Classic is referred to as a "non-destructive editor" and as such does not, by default, make changes or adds info to the original imported file. To achieve that you have to manually select to do so or select to have that automatically done in the Catalog Preferences. See the screen capture of the dialog box which shows the available options.
By Default Lightroom only Reads and Writes to the Lightroom Catalog file.
Whenever you save metadata, it is written into the dng file, no matter what catalog settings you have.
Absolutely, it will save the metadata to all selected image files, DNG, Raw, Tiff, Jpg, PNG and PSD. It will also happen if you have the Auto Write selected.
Not RAW. For RAW the metadata is saved to an XMP sidecar
Yes, the sidecar sits alongside the RAW file and is specific to that file. For DNG file because of its structure the metadata is stored in the file header, The original poster is saying he does not wish that to happen.
Then all he has to do is not save metadata to file and not select the Auto write to xmp.
The manual "Save metadata to file" does the same thing as the "Auto save to XMP".
The metadata will be saved to the file header of the DNG file, if you do not wish that to happen then do not select either function.
If you turn on "automatically write changes to XMP, LR starts to save XMP files for All your edited files, not just the files you selected to save metadata for. So that's not an option. And even with that option on, LR writes metadata in the dng file also.
You do not want that option ON, you want that option OFF, because you want Lightroom to not write to your DNG files. You also want to not use the command Metadata->Save Metadata to Files. In this case, nothing is ever written to your DNG files.
And as I said earlier, you need to make backups of all of your DNGs just in case you accidentally use one of these options/commands, so you always have a pristine copy of your DNG available.
Actually LR does NOT change the image, Sensor, Data of a DNG file. What it does do is IF You Edit a DNG and you have the option turned on to Auto Write changes to a Sidecar XMP file those edits get written into a special section of the DNG file but it does not Change the actual data that make up the image.
Only LR or ACR can Read and (This is the BIG part) DISPLAY those edits over the top of the original DNG image data. If you open that same DNG in some other editor youy will not see the edits you did in LR.
Even if it doesn't modify the image/sensor part, it's still modifying the files which is extremely painful for people valuing their photos. To ensure not to lose my pictures I do 3 different copies (NAS, AWS S3 and USB disk). But just changing a single bit of the file means that's it's a new version so S3 Glacier becomes useless because I have to pay for each version of the file. Same for synchronization with copies on hard drive and NAS, if I took time to put keywords then it means hours of synchronization because the tags are written to the files. And even if I enable XMP writing, it's still changing the files.
And with Lightroom CC it's even worse. Putting a keyword in Lightroom Classic synchronized copy means reuploading the entire file. When you're travelling or don't have a super high-speed fiber internet access, it's a nightmare.
I really don't understand why Lightroom (Classic or CC) is doing this, especially as we still have GB of catalog.
I'm not sure what you are seeing. If you turn OFF the option to automatically write metadata to XMP, your DNG files should not be changed, not even by one byte.
To me, it looks like this:
If "Automatically write changes to XMP" is ON, Lr seems to write all metadata changes and all edits in the devlelopment module in XMP format, and that XMP data is saved as a sidecar .xmp file for RAW and JPEG formats, but the XML data seems to be embedded into the image file for the DNG format (ie, no sidecar for DNGs). That means that every edit changes the DNG file and will force it to be backed up again.
If "Automatically write changes to XMP" is OFF, Lr doesn't seem to change the DNGs but also doesn't seem to write .xmp sidecars for other formats. In this case, all metadata and edits will probably be in the catalog database only.
I feel that Adobe should add an option to save the XMP data as sidecar files also for DNGs. If you work with DNGs heavily, constantly backing up full DNGs over and over is a real burden, esp. for cloud backups.
Not having XMP at all, on the other hand, could be detrimental to one's workflow if you use external tools. Example: DxO PureRAW, a RAW development software, generates DNGs from the original RAWs, and if you import these DNGs into Lr, a newly imported pictures will have all edits of the original RAW file automatically applied.
yes, this is the main reason to not use dng... no sidecar and backups are a pain.
Camera Raw has a Preferences setting to create XMP sidecar files for DNG files. I suggest creating an 'Idea' post to provide this capability as a LrC Preferences option.