Problems with DNGs created by Adobe Camera Raw (ACR)

Started by anmue, March 29, 2015, 09:11:54 PM

Previous topic - Next topic



Today I made some experiments to see if DNG will give me some benefits. I like the workflow and the advantages that Carlo Didier described in another thread:

Quote from: Carlo Didier on September 30, 2014, 11:05:53 AM
In my workflow, I first ingest images from the camera (not native DNG, but currently NEF) to an SSD with Downloader Pro (which at ingestion adds some metadata like copyright, etc and does the geotagging using GPX files from my GPS).
Then I check and cull the images with Adobe Bridge, completing some metadata if necessary.
After that, I may do some more geo-coding with GeoSetter (to insert location information like country, city, etc).
After all that is done, I convert the remaining files to DNG and copy them to their final drive/folder.
Last step, I ingest the new images in iMatch.
As Bridge updates the DNG embedded JPG previews, iMatch uses those and I see the "developed" version in the thumbnails in iMatch, thus not needing an additional developed JPG beside the raw file.

Advantages? One file only per image. Embedded "developped" preview if you use ACR (Bridge or Lightroom). One format for all images, even after having changed cameras several times.


So I edited some .NEF files with ACR (mostly the white balance) and converted them to DNGs using different options (lossless compression, with embedded JPEG - medium and large, without JPEG etc.). Then I imported the DNGs into Imatch (5.3.14).

The result was a little bit disappointing: I expected to see the changes I made in ACR also in the Imatch, but only one file showed the corrected white balance in the thumbnails. The other files showed the unedited version. The astonishing was that the DNG, which showed the correction in Imatch was a version without an embedded JPEG and I was not able te reproduce the result  :-\ . For one DNG Imatch wasn't even able to create a thumbnail!

Can anyone give me some hints, what might went wrong. I use a rather old version of ACR (5.0). At least I was able to try a little bit newer one (6.7 from PSE), but the results where the same. So I don't think there is something wrong with my ACR.

Addendum: I just tried to look at the one file that worked in the thumbnail in the Imatch viewer and there it is also the uncorrected version :-(

Regards, Andreas

Carlo Didier

Strange, I never had any problems like yours.
Attached are my settings to save to DNG from ACR.
As you used an older version, maybe your camera isn't supported. What is the model of your camera? Can you try the standalone DNG Converter from Adobe?

[attachment deleted by admin]


Dear Andreas,

I use DNGs in much the same way as you are proposing and for much the same reason: accurate previews and thumbnails in iMatch.

The settings I use are full-size jpeg preview and NONE of the other boxes (fast load data, lossy compression, embed original). As a bit of an Adobe captive, I'm up to date with the ACR version, but this approach has been working for me for some years, so I'm not sure the version is too important, if you aren't reaching too far back. Version 5: not sure.

Sometimes, iMatch will not generate a thumbnail image at all from a DNG, apparently at random. My workaround is to reopen that image in ACR and either make an infinitesimal change in a parameter, eg increase shadow depth by 1 and resave ("Done" button) or force  a refresh of the embedded jpegs (click on black triangle at extreme RH end of the Basic toolbar and select "Update DNG previews" from the drop-down menu). If that option is greyed out, make the infinitesimal change and proceed. iMatch should then quickly pick up the new preview image.

Hope that helps,




I just downloaded the newest standalone converter. Using the converter doesn't help either. I additionally extracted the JPG out of the DNG using exiftool. The JPG shows the editing I made on the original NEF. So it is correct!

This is very confusing  :-\.

BTW: The camera is a D700.

Regards, Andreas


Let me just add my experiences to this topic:
When I use ACR to convert NEF to DNG (I usually compress the DNG version - a compromise) all works well
except when I convert an  image to B&W - there DNG seems to deliver an off-colour thumbnail.
The dngconverter I found does not embed the ACR settings in the DNG file. This then required an additional propagation step
in Imatch. Because of this I stopped using dngconverter.

Since I keep a "developed" jpg of each raw file I rather not have the DNG thumbnail show the developed version.
Anyone know if this can be achieved by settings?


Unfortunately, Adobe seems to have ruined the initial idea of DNG for good. By adding new stuff to the DNG format every time they needed something for their software, they created so many flavors and variants of DNG that it is not funny anymore. So much for 'standards' and Adobe.

That said, problems related to DNG files (not loading in IMatch, preview not detected etc.) are always caused by the installed WIC codec (there is one from Adobe, one from Microsoft, one from FastPictureViewer and maybe others as well) and whether or not it supports the 'features' of the DNG variant used. IMatch pulls in DNG files via whatever DNG codec is installed on the system, and whatever the codec returns is used. IMatch has no way to tell if the DNG codec has processed the file 'right' or not.

Installing the latest codec (whatever you use) is mandatory. Usually 100% embedded previews are the best way to avoid any kind of trouble. Adobe writes instructions into the DNG XMP which only their own render engine can interpret. If you don't use embedded previews (or the codec you have cannot read those) your DNG files will look different in IMatch or other software than they look in Adobe products.

See slso WIC Support and Codec Availability in the IMatch Knowledge Base for more info.
-- Mario
IMatch Developer
Forum Administrator  -  Contact & Support - Follow me on 𝕏 - Like on Facebook

Carlo Didier

Maybe then I never got problems because I use the excellent FPV codec pack (and FPV itself).



I finally installed the FastPictureViewer Codec Pack and the anomalies vanished :-). Now Imatch shows the embedded JPEGs. Thanks to Mario. His post was the essential hint.




It's amazing how many codec problems are solved by installing the FPV codecs.