External sidecars for DNG in LR 5.7.1

[GrahamBy]

Dear all, while ctrl-s in LR 5.7.1 writes external sidecar files to read-proprietary image files, there doesn't seem to be an option to do this when the source file is a dng. The problem comes from using a Pentax, which writes dng files directly on the memory card. According to the pop-up, edits to dng files are written directly into the file.

This is a problem if one should wish to move to a different editor which expects external xmp sidecars, which it is able to translate (at least partially). In my case, that is darktable.

Is there a setting somewhere to force external sidecars?

I tried setting a dng to read-only ("writing refused") and in that case nothing was written at all.

[Aram Hăvărneanu]

No, but any application that reads DNG should not expect XMP sidecars.

[GrahamBy]

I think you'll find that darktable, RawTherapee and non-Adobe, non-destructive editors all use external sidecars.

[Aram Hăvărneanu]

This can't work, when encountering a DNG+XMP combo ACR will delete the XMP without notifying the user. Terrible behavior if you ask me, but it is what it is.

File a bug with other software about embedding the metadata in the DNG directly. Or perhaps file a feature request with Adobe, but good luck with that.

For the record, I also wish I could use external sidecar with DNG files, but the practical reality is unfortunately different.

[GrahamBy]

I don't know what world you're living in... but this doesn't happen when using LR in Windows. Maybe later versions? Anyway, that's not my problem.

[john beardsworth]

There's no LR option to create sidecars for files like DNGs which allow embedded xmp. The read-only trick only works in Bridge.

[digitaldog]

As John points out, there's no reason to ever need a sidecar for DNG's; all the necessary data is written into that container. Adobe doesn't write sidecar's for DNGs. Sidecar's from Adobe is solely used for proprietary raws as Adobe treats them as 'read only'.

[GrahamBy]

As John points out, there's no reason to ever need a sidecar for DNG's;

Unless one wishes to leave the Adobe world, which I do.

Anyway, the solution is to install exiftool, which has an option to extract tags form a DNG and write them in an external file. Said file is then readable by a non-Adobe editor.

This is the command, although it tends to be limited by W10 security features:

exiftool -xmp -b -w xmp "c:/folder1/folder2/filename"

[digitaldog]

Leaving the Adobe world while using their DNGs; hilarious
What’s next? Sidecar files for TIFF, PSD,JPEG, PSB? 🤪

[john beardsworth]

Unless one wishes to leave the Adobe world, which I do.

You seem to think sidecars are the norm. They're not - they are just for undocumented file formats. As Andrew points out, DNG is the same as file formats like JPEG, PSD, TIF etc which are designed to encapsulate their own metadata and not carry around sidecar files (I think Peter Krogh referred to them as colostomy bags!).

Historically, this has been a big advantage outside the Adobe world. Embedded metadata means most apps haven't needed to add their own code to look for sidecars or try to figure out all the complexities that their presence introduces (eg how to reconcile sidecar versus embedded metadata).

[GrahamBy]

Leaving the Adobe world while using their DNGs; hilarious
What’s next? Sidecar files for TIFF, PSD,JPEG, PSB? 🤪

Andrew, you've quite a lot of expertise, so I don't understand the source of your insecurities. If one owns a Pentax (or Leica, if you want cred), it writes DNG files on the memory card. They are just raw files for me. The fact that DNG is likely to be supported over a long time span (which you've pointed out in response to various rants by proponents of sticking to ASW or NEF formats) is an additional advantage.

As it happens, darktable and Raw Therapee both read and treat dng in this way. If I had a Sony or Nikon or canon or etc, it wouldn't be an issue. The fact that these programs write explicit sidecars has several advantages, such as being able to copy the xmp from one file and paste it to another. These happen to be legitimate processing choices which I feel no need to argue for here. So far, they appear to do what I want. Maybe Adobe pisses in your pocket to encourage you to mock any alternative route, but in any case they don't give me any reason to hand them more money to keep using technology which was sufficiently developed for my purposes as soon as they went 64 bit.

Or maybe you're right, I'm a deluded fool, but just at the moment your comments make you look like a sad prick.

[digitaldog]

Andrew, you've quite a lot of expertise,

Indeed, one rare example of an accurate statement you've provided here. In April, I'll celebrate 30 years 'buying into' the Adobe (Photoshop) workflow. Never has that product nor the industry it services needed to write sidecar files for the formats it writes. I'll point out you failed to answer a simple question about writing such sidecar files to TIFF, PSD, JPEG, PSB etc.

so I don't understand the source of your insecurities.

You don't understand a lot and you do make a lot of assumptions like the sentence above about insecurities. Two of us have tried, and failed to have you comprehend what sidecar files were designed to do and why with respect to DNGs vs. Proprietary raws.

If one owns a Pentax (or Leica, if you want cred), it writes DNG files on the memory card. They are just raw files for me. The fact that DNG is likely to be supported over a long time span (which you've pointed out in response to various rants by proponents of sticking to ASW or NEF formats) is an additional advantage.

I own Sony and Canon, they do NOT write DNG files on memory cards that are also raw and I go out of my way to convert them to DNG. So in that respect, we are in violent agreement (expect wait, you have no choice and I do....).

As it happens, darktable and Raw Therapee both read and treat dng in this way.

As it happens, Lightroom, ACR, treat DNG's in this way; they do it as designed and embed the XMP metadata, like other file formats DIRECTLY into the document container. Like a big pile of other document types. I don’t know if you are purposely trying not to understand this fact, or if you are really struggling with it.

If I had a Sony or Nikon or canon or etc, it wouldn't be an issue.

There is no issue. There are misunderstandings, that's very clear. 

The fact that these programs write explicit sidecars has several advantages, such as being able to copy the xmp from one file and paste it to another.

That isn't how nor why sidecar files were designed with respect to DNG and a hell of a lot of other file formats. Pasting XMP from file to file isn't at all an attribute of sidecar files and lots of products can do so without them.

These happen to be legitimate processing choices which I feel no need to argue for here.

You're not auguring. You're not learning either it seems. 

Maybe Adobe pisses in your pocket to encourage you to mock any alternative route, but in any case they don't give me any reason to hand them more money to keep using technology which was sufficiently developed for my purposes as soon as they went 64 bit.

The absurd is the last refuge of a pundit without an argument. There's been no mocking; only facts about how DNG's in LR actually work.

Or maybe you're right, I'm a deluded fool, but just at the moment your comments make you look like a sad prick.

I DO understand the source of your insecurities!    And your need to get nasty which is really what's sad here. Keep this in mind bud:
"What annoys us about others may say more about ourselves than about them."-C.J. Jung