P: Exporting DNG (from Merge) as a new DNG w/ Compatibility set to 14.0 creates a damaged file

[John R Ellis]

Exporting a photo-merged DNG as a DNG with compatibility Camera Raw 14.0 And Later creates a DNG that can't be opened in either Photoshop Camera Raw or in LR Develop.

Tested with LR 13.2 and Camera Raw 16.2 on Mac OS 14.2.1.

1. Open this small catalog:

https://www.dropbox.com/s/dzg9nvdz727wgam/merge-export-dng-bug.2024.03.25.zip?dl=0 

2. Select both photos and do Photo > Photo Merge > HDR with these settings:

3. Select the merged DNG and Export with these settings:

4. Open the exported DNG in Photoshop and observe the error "The file appears to be damaged":

5. Import the exported DNG into LR, go to Develop, and observe the error, "The image appears to be damaged":

6. Repeat step 3 with Compatibility: Camera Raw 15.3 And Later, and observe the exported DNG opens without error in both Photoshop and LR Develop.

[Adil36199917kev4]

Hello

I am a real estate photographer and I use HDR bracketing for many of my clients in cluding Airbnb. My normal work flow is to import bracketed RAW files from my Sony A7C into Lightroom Classic (13.2). I then group each bracket into a stack and then select all stacks and right click "photo merge to HDR". This then bulk processes all of the stacked images to generate HDR images in DNG format. One of my clients needs to receive the merged HDR files in DNG format which has worked flawlessly these past two years. However on my last two jobs for ths client the client reported that the merged HDR DNG files I have submitted were corrupted.

I have done analysis on this and can easily recreate the problem. I am running an apple macbook pro M2 running Sonoma 14.4. If I select one of the processed merged HDR files and export it to DNG format - on the surface all looks OK with no errors reported on export. However if I try to upload the exported DNG file back into lightroom or photoshop I get an error message "The file appears to be damaged".

However if I import the same file into a non adobe product like Affinity Photo I get no error message. If I export the same HDR merged DNG file from Lightroom Classic to a diferent format tiff or jpeg there is no issue when reloading that image back into lightroom. I have have also tried exporting as format set as  "original" which also creates a DNG file on export albeit much smaller resolution than the original DNG exported file. This file can also be loaded back into Adobe products without error.

The work around I have to do is take the exported HDR DNG files and run them through Adobe DNG Converter which looses some resolution as the image reduces slightly  in size after this process. These files can then be uploaded back into Lightroom Classic and Photoshop without ereror messages.

Seems Lightroom may experience issues when exporting merged DNG files as a DNG file?

Anyone else had this issue and can advise?

Many thanks

Adil

Brighthouse Photography Limited

[Lumigraphics]

Are you using local storage (not cloud/network?) And try changing the file extension from .dng to .tif, what happens?

[Adil36199917kev4]

The client requirement is to receive merged HDR files in DNG format. If I export in any other type of format e.g tiff, jpeg, etc there is no issue re-importing those to Lightroom.

[Adil36199917kev4]

I am exporting to local drive. Have tried exportig to my hard disk on my MacBook pro and get same result.

[JohanElzenga]

Lightroom Classic 13.2 introduced a new compression method (jpeg XL) for the merged DNG, which greatly reduces the file size. Export as DNG does not (yet) use this compression as far as I know, so that may explain why exporting a merged DNG as DNG again might create problems. It is also not necessary. As you found out, you can simply export 'as original', because the original is already DNG. In both cases the edits and other metadata will be written into the header of the DNG, so they'll be retained.

[Adil36199917kev4]

This solution does not work, when exporting using "Original" the DNG file size reduces by comparison  from 92.1MB to 18.4MB so lost a large amount of resolution.

[JohanElzenga]

Not necessarily. Do not jump to conclusions based on just the file size. File size and resolution are not the same thing! A Denoised DNG contains a copy of the raw data. Export Original may strip those and that may explain the smaller file size.

[Adil36199917kev4]

Thanks Johan - Adobe are now on the case looking at the issue. I am not a heavy user of Adobe products and tend to do RAW editing with CaptureOne. However some clients require editing with Adobe products. This problem has only occrrued for the last two jobs I have performed the first being on the 1st of march 2024 . Prior to that date I had no problems at all.

The exported merged DNG file eoors when opened by online versions of Photoshop and Lightroom. I have performed some tests today and Affinity Photo, Affinity Publisher, Affinity Designer, Aurora HDR, Luminar 4, Apple’s Preview Application and Topaz DeNoise  AI applications could all open the same file without error. I noticed that Camera RAW , Lightroom and Lightroom Classic were all updated in February 2024 and the first incidence of this issue I observed  was after a photoshoot I perfoemed on 1st March after the software updates were issued, so I am convinced the previous software upgrade to these products has introduced this issue and I suspect the common denominator in all of this is Camera Raw's dealing with the exported HDR merged DNG file. Its also strange that running the "corrupt" DNG files through Adobe DNG Converter so that you convert DNG (corrupt format) to DNG seems to  fix the issue? So something to do with the Lightroom Classic export function or camera RAW is where I beleive the issue is.

Regards Adil

[Lumigraphics]

I just did some testing and am unable to reproduce this issue. A merged DNG opens fine in ACR.

[KR Seals]

You can always revert to an earlier version of LrC 13 in the Adobe Creative Cloud app.

[John R Ellis]

"if I try to upload the exported DNG file back into lightroom or photoshop I get an error message "The file appears to be damaged".

I'm not able to reproduce this problem either. In general, Adobe only pays attention to problems that they can easily reproduce. I suggest as a next step that you upload the original photos, the merged HDR DNG, and the exported merged HDR DNG. We can see if we observe the same symptoms in other LR configurations and are able to make a reproducible bug recipe for Adobe's attention.  

Upload the photos to Dropbox, Google Drive, or similar and post the sharing link here.

[John R Ellis]

"However on my last two jobs for ths client the client reported that the merged HDR DNG files I have submitted were corrupted."

Beware that if the client is running older versions of LR or Photoshop/ACR, they may not be able to open DNGs created by the latest versions of LR Merge. The latest versions of LR will use DNG Version 1.7, which was introduced last fall, I think. So versions of LR/PS/ACR prior to then won't be able to open them.

To work around that, export the DNG with File Settings > Compatibility set to use an earlier version of Camera Raw.   (Subtract 3.0 from the CR version to get the corresponding LR version, e.g. CR 12.4 is LR 9.4.)

[Adil36199917kev4]

Thank you john for this information. When I try and open the merged exported HDR file with PS/LS/ACR they were the latest versions of all products LRc/LR/ACR/PS. For clarification the merged HDR DNG file was created using LRc 13.2 and when exported i was tryig to open with LR version 7.2 and when opening with PS/ACR I am using PS version 25.6 and ACR version 16.2

Hope that helps.

[Adil36199917kev4]

Here is a selection of 10 merged HDR files which were created using LRc 13.2 and exported as DNG files specificying "Using Camera RAW 14 or later" option.

https://www.dropbox.com/scl/fo/l77q4xdueyubzrcdpi80p/h?rlkey=3qm17a46s62ipc2jjer2utk0u&dl=0

If you try and open using LR or PS/ACW you should get to see the error message I am getting. If you try and open with another application like Affinity Photo no error message.

Hope this helps.

Adil

[Adil36199917kev4]

Hello

In an effort to help you re-create the issue can I suggest the following.

I have downloaded 15 RAW files directly from my camera that were used for the photoshoot in question and uploaded them to my drop box. Please can you follow the EXACT workflow I am using with LRc 13.2 to create the merged HDR files. I have used three different exposures for each bracket , making 5 images when merged to HDR.

https://www.dropbox.com/scl/fo/fhhqp5v0i9mlrki4vwbig/h?rlkey=0fwdlfwsu6i6wvygczqar2r8i&dl=0

Please follow the exact workflow process I am using as follows:-

• If possible please use a MAC Running OSX Sonoma 14.4
• Please download the RAW files to your desktop
• Open Lightroom Classic 13.2 
• Select Import and select the 15 RAW files and import them into LRc 13.2
• In LRc 13.2 either manually stack each group of three RAW images so 5 Stacked images exist or select all the RAW files and right click any of the selected images and select Stacking>Auto Select by Capture Time and adjust setting so that a total of 5 stacks appear.
• Select all of the stacked images and right click and select Photo Merge >HDR
• Once the process is complete please select the 5 merged HSR DNG files for export.
• Select Export and set the file type to DNG | Select camera RAW 14 or later  | set jpeg preview = Medium Size
• Export the Images 
• Using the latest version of LRc see if you can import these Merged HDR DNG files back into Lightroom for editing and also right click on any of the exported DNG files and select open with LR or PS/ACR to see if you can recreate the error message
• If you can recreate the error message please try and open the same file using a a different (Non Adobe) application which supports DNG file format.
• Let me know the results.

Thanks 

Adil 

[Lumigraphics]

Why are you exporting a DNG file to DNG? This makes no sense if you just created a DNG. Just use that.

[Adil36199917kev4]

Its a requirement from the client to receive files formatted in a certain way and they have specified specifically exporting to DNG with to support ACR 14 or later and with very specific file names. Having said that I located the original merged file in my catelogue and used the "open with" command in OSX for both PS and LR. PS was able to open the file without error whilst opening the same file with LR reproduces the same error message.

[Adil36199917kev4]

I have enclosed copies of the original Merged DNG files in my catelogue  - these have not been exported from LRc and are copies of the orginal merged HDR DNG files within my catelogue.  Please try and open these with LR and PS and let me know what happens?

https://www.dropbox.com/scl/fo/bgiske5hhgs9szbsvehfv/h?rlkey=11iqn4hygl3ni7wv33958dvkm&dl=0

Thanks

[Adil36199917kev4]

Lightroom Classic is up to date, can you. be specific on what export preferences I should be looking at as their is no "export tab" under preferences to check? There have been no reported errors on export from LRc throughout this process. I am engaged with Adobe support on this issue. Will try to reset preferences as described.

Thanks

[Lumigraphics]

You don't open files with Lightroom, you import them. Is this the problem, you've been trying to open DNG files with Lightroom? AFAIK, the only thing Lightroom opens is catalog files.

[John R Ellis]

I was able to reproduce the problem given your detailed instructions and filed a bug report with simpler steps. A workaround is to select Compatibility: Camera Raw 15.3 And Later.

[John R Ellis]

Moderators, @Rikk Flohr: Photography, please merge with this bug report:

https://community.adobe.com/t5/lightroom-classic-bugs/exporting-photo-merged-dng-as-dng-compatibilit...

[Adil36199917kev4]

Hello another workaround is to export as  "Original" as opposed to DNG

[Rikk Flohr: Photography]

Adding bug number and updating status.

[Adil36199917kev4]

Hello I have tried setting Compatibility: Camera RAW 15.3 or later Lightroom develop still fails however PS works without error - the same if I export choosing "Original"