Problem with third party DNG-to-JPEG image converters

[pavlek99107747]

I have a new, more powerful desktop PC with Windows 11 and with it comes a problem I have never encountered before on my old PC and Windows 10.

The problem: third party image converters, such as XnConvert and a bunch of others I tried in the last days, fail when it comes to converting DNG files edited in and exported from Lightroom Classic into JPEG files. In all cases the DNG-to-JPEG conversion runs seemingly normally, but the produced JPEGs contain absolutely none of the edits featured in the DNG files. Instead, the produced JPEGs appear to be the converted versions of the unedited, raw files (Nikon NEF). Notably, exporting to DNG or JPEG from LRC works just fine, but LRC is not the best option for batch conversions.

I would be thankful for any ideas or explanations.

[dj_paige]

Edits created by Lightroom Classic and stored in a DNG are proprietary, and can only be interpreted by certain Adobe software. Non-Adobe software can't use these edits at all.

... but LRC is not the best option for batch conversions.

LrC does batch exports of JPGs from DNGs.

[pavlek99107747]

dj-paige,

Thank you for the response. As a matter of fact, I have used XnConvert for years to convert LRC-edited & exported DNGs into high-quality JPEGs without any issue. All the edits made in LRC were contained in the produced JPEGs. As said, those were Windows 10 times, but I am not quite sure that the trouble has to do with Windows 11.  I have checked all export settings in LRC (version 13.5, new) and all output settings in the latest update of XnConvert (and some other image converters) to no avail. Neither XnConvert nor other converters can convert edited DNGS anymore. As to the batch conversion DNG-JPEG in LRC: yes, it can be done, but once the DNGs are exported to folders outside LRC, it is much easier and faster - for me at least - to convert them from there with other software such as XnConvert.

[Bill Sprague]

Could this be an XnConvert issue rather than a Lightroom issue?  Does their support offer a suggestion?

[richardplondon]

Exporting to DNG assumes the output is intended to act as a Raw (or a mock Raw equivalent, if exporting to DNG from say a camera JPG). By this I mean that it creates a duplicate of the unedited DNG as imported, but attaches metadata describing your edits. Same as when exporting choosing the filetype selection "Original". So that is functionally equivalent to writing edit metadata back to the external file which has been imported, and then inspecting that - except, the latter method could not externally save the edits of a virtual copy, while you can do so via Export.

The embedded file preview of your imported DNG, or of an exported duplicate, may or may not reflect latest edits depending on the exact steps followed.

So it depends what XnConvert is referring to - extracting whatever preview image is present? Carrying out a default Raw conversion? Or (less likely IMO) carrying out a full Raw conversion and adjustments by correctly interpreting all of the Adobe proprietary editing parameters that are found attached. Perhaps by looking at these DNGs in your file browser and seeing what the thumbnail looks like (which should refer to the embedded preview as that currently stands AFAIK) some clues may be gleaned. I have just now desaturated a DNG based image, then exported a copy of that to DNG. The file previews properly as B&W within the file browser. But opened into a non-Adobe aware program (I tried Affinity Designer) the image is interpreted and displayed as if I had never desaturated it. So that program is neither extracting the (B&W) preview, or using the (B&W) editing instructions that LrC will have included. 

Incidentally, as I understand it editing a DNG will not in itself update the preview image present within the imported file. That needs to explicitly be made happen.

[John R Ellis]

Almost certainly, XnConvert is reading the previews in the exported DNG. 

In Export, when you select Image Format: DNG, LR always includes fully rendered previews of various sizes (which include all Develop edits) in the DNG.   When you select Image Format: Original, the included previews may or may not include the most recent Develop edits, depending on whether you've done Metadata > Update DNG Previews & Metadata.

Troubleshooting steps:

1. Make sure you've selected Image Format: DNG in Export.

2. Try changing Compatibility: from Camera Raw 15.3 And Later to Camera Raw 14.0 And Later. DNG version 15.3 introduced JPEG XL compression, which LR often but not always uses for the embedded previews, while 14.0 uses JPEG compression. The order of the embedded previews within the DNG also changed.  It may be that XnConvert is getting confused by these changes.

[pavlek99107747]

Many thanks to everyone for the support and ideas. 

I also thought that the issue could be with XnConvert and not LRC, but upon contacting them I received an answer which indicates that they did not understand the problem.

I will try the compatibility change later today, when I get back home.

[Lumigraphics]

I'm not surprised, you need a converter that can read the DNG and the Adobe-proprietary edits to correctly create a new file. I'm not sure if anything other than Adobe products will do that, especially things like the new AI features.

Try exporting from Lightroom, either directly to JPEG or to an intermediate rendered format like TIFF.

[pavlek99107747]

Hi,

Thanks for all responses. I want to empasize again that the conversion of LRC-edited DNG to JPEG has worked perfectly well for years, with XnConvert and a bunch of other convertes. The porduced JPEGs were of excellent quality despite the lesser size. The conversion stopped working properly after my switching from Windows 10 to Windows 11. I doubt it to be the cause of the problem though, perhaps it has to do with the latest LRC updates. Anyway, I have checked and rechecked all settings, everything is as it is supposed to be. In the meanwhile I have sent a LRC-edited DNG image to XnConvert asking them to check it and inform me what the problem is. Still waiting for their answer.

[John R Ellis]

Did you try changing changing Compatibility from Camera Raw 15.3 And Later to Camera Raw 14.0 And Later?

[John R Ellis]

I tried Mac Xnconvert with LR versions 13.5, 12.0, and 10.4, with Export Compatibiity set to 15.3, 14.0, and 12.4. When converting a DNG edited and exported from LR, it consistently failed to read the correct embedded preview from the DNG containing the fully rendered edits. 

(Xnconvert wouldn't let me install the x64 version on my WIndows 11 ARM, even though it fully emulates x64.)

However, the following programs do read the correct embedded preview (rendered with LR edits):

Mac: Xnview

Windows: Photos, Irfanview, Faststone, Snipping Tool

So the issue is almost certainly with Xnconvert.  Perhaps you were previously running much older versions of LR and Xnconvert.

[pavlek99107747]

Thank you, johnrellis.

Yes, I have tried the compatibility change, to no avail, and I am getting pretty sure that the issue is with XnConvert. I have been waiting since days for their response, after sending them a LRC-edited DNG image to check the issue for themselves. Thanks for the tips regarding other converters, I'll check them out.

By the way, another issue that definitely has to do with Adobe: when signing in, I have to request Adobe at least three times to resend the identity verification code to my cellphone...annyoying.  

[pavlek99107747]

johnrellis: none of the software sou suggested managed to convert DNGs with LRC edits into JPEGs. I tend to change my mind and start believing that this conversion problem has to do with LRC after all; be it the import or export settings, new updates, etc. I can understand Adobe’s lack of interest to go into this, but the easiest way to find a solution would be to ask an Adobe expert to try to convert a DNG with LRC edits to JPG, using either XnConvert or any other third-party converter. Any chance for that, Adobe? If it works, please let us know the proper settings, and if not, please explain why.

[Lumigraphics]

It can't be done completely at present. Adobe has proprietary editing tools and have added a bunch of stuff with later ACR/Lightroom versions, they now have a second sidecar file in some instances. A third-party developer would have to reverse-engineer those edits and apply them, even assuming that the third-party app HAS comparible tools and features.

Darktable has partial support, but not complete, for example.

https://docs.darktable.org/usermanual/3.8/en/overview/sidecar-files/sidecar-import/

[pavlek99107747]

Thanks, Lumigraphics.

Well, that's it then. I will just continue to do what I am doing these days: export edited raw files from LRC to both DNG and JPEG. As I never import and edit more than 10 images at once in LRC, this will be a bit tedious, but it does the job. 

[John R Ellis]

"johnrellis: none of the software sou suggested managed to convert DNGs with LRC edits into JPEGs."

All these viewers read the fully rendered previews embedded in the DNGs -- they don't attempt to interpret the LR Develop settings and apply them to the raw image. I know of no image viewer/converter that tries to interpret LR Develop settings. If Xnconvert was at some point displaying the rendered edits of DNG, it was surely reading the embedded previews.

I've attached a screen recording of LR 13.5 / Windows 11, showing edits being applied to a DNG, the DNG exported from LR, and the following apps correctly viewing the edits in the exported DNG: Photos, Irfanview, Faststone, Snipping Tool.

All my testing with these viewer/converter apps and many versions of LR indicates that LR Export of DNGs has continued to work as expected and includes fully rendered previews in exported DNGs that the apps access. I don't know what explains what you're seeing. As a next step, I suggest the following troubleshooting steps:

1. In LR, select a DNG and apply some edits to it.

2. Do Metadata > Save Metadata To File.

3. Export the DNG with the settings Image Format: DNG, Compatibility: 15.3, JPEG Preview: Full Size, Embed Fast Load Data.

4. Upload the original DNG and the exported DNG to Dropbox, Google Drive, or similar and post the sharing link here. We can see if these apps on other systems correctly display the edits.