Does anyone incorporate DNG (not in-camera) in their workflow?

[lnh]

At first glance, the notion of an archival format in combination with a DAM such as IMatch makes sense, and I'm just curious if anyone has had experience with this approach. I've read some articles which espouse the virtues of DNG, but often wonder if these are written by people so close to Adobe that you should be suspect of their advice. It appears all metadata is written into the DNG so I'd imagine it might make a DAM very slow compared to writing tiny sidecar files. I know other apps like DxO Optics Pro can generate DNG's but can't read them except where it's the native format coming out the camera. Not sure if other RAW converters, Adobe products aside, handle them or not.

Just playing around with the DNG converter from Adobe, its singular use I've found interesting is an ability to convert RAW files from cameras not supported by my older version of ACR in Photoshop (CS5) so they can opened in Photoshop. That is a nice trick, but doesn't have much to do with general workflow or DAM integration.

[jch2103]

In my case, I've got DNG files generated as 'raw' files by VueScan from slide or negative scans. These aren't camera files, of course. They're designed to allow reprocessing of scans with VueScan without having to actually do a new scan. I can't open them with DxO, but that's not really an issue. I've set up Relations for the output jpg files.

[cytochrome]

.... It appears all metadata is written into the DNG so I'd imagine it might make a DAM very slow compared to writing tiny sidecar files. I know other apps like DxO Optics Pro can generate DNG's but can't read them except where it's the native format coming out the camera. Not sure if other RAW converters, Adobe products aside, handle them or not.
...

I do not use DNG so have nothing to say about them. However I do not use XMP sidecars either and write metadata directly to the raw files. DNG are certainly not "worse" than raw speed-wise.

With the raw it is perfectly doable (I do it!!), should be OK with DNG. I would do some tests on a small DB to make sure that everything (xmp, iptc, exif, keywords.. diacritic characters) get written as you want and can be retrieved easily. It takes a recent PC however, otherwise you will look at a lot of white screens...

Francis

[lnh]

I do not use DNG so have nothing to say about them. However I do not use XMP sidecars either and write metadata directly to the raw files. DNG are certainly not "worse" than raw speed-wise.

With the raw it is perfectly doable (I do it!!), should be OK with DNG. I would do some tests on a small DB to make sure that everything (xmp, iptc, exif, keywords.. diacritic characters) get written as you want and can be retrieved easily. It takes a recent PC however, otherwise you will look at a lot of white screens...

Francis

No worse unless you choose the DNG option to embed the RAW . However, wasn't planning on using that option.

I keep the IMatch DB on a locally attached SSD, and also keep my in progress files for IMatch and general DxO/Photoshop manipulation etc on the SSD as well. Once it's set the way I'd like, the files get moved to a NAS via a 1Gb ethernet link. As long as I don't pile on a bunch of changes once it's on the NAS, the setup seems to work fine. Even if it takes time, I just let IMatch work away as long as I see resources being used in the task manager by either IMatch or exiftool. It eventually comes back.

One of the benefits of DNG is a built-in checksum to assure file integrity. I've read that Lightroom can perform this test, but I don't believe IMatch has that capability at this time although I haven't checked through all the scripts out there. The idea of file integrity makes sense and is in line with the concept of a fundamental capability you'd like to get out of a DAM product, so maybe I'll put that idea in the future features ideas area assuming a script isn't already there.

[Erik]

In terms of what you are discussing, I did begin incorporating DNG into my workflow as my old Pentax camera's RAW files were not well supported and the DNG files run through Adobe's DNG converter were more compact that the PEF files the camera made.  I found that the files were as good as RAW files were for processing and actually eliminated most of the original RAW files the DNG files were derived from.  The DNG files have been as good as RAW.  My current Pentax camera shoots DNG, so I just stuck with the format. 

After processing a file, however, I have not used DNG after processing.  DxO has no problem opening my DNG files, but I think that's because it determines whether it will open a DNG file based on metadata, and DxO thinks all files made by a Pentax camera were made in the camera.  This leads me to think that DxO may be able to open most DNG files if the metadata was just right.

I know Lightroom and DxO can output DNG files, but I'm not sure of an advantage in doing that.  I generally export Tiff, PSD, or JPG files after I've done any processing.  I think I would generally rather be able to open a processed file directly in Photoshop or in any other software directly, and most pixel based editors rather work with a Tiff or Jpg file than a DNG (or PSD file even). 

I'm not sure I've ever noticed a huge problem with metadata, but I could see an issue if a person is working with an incremental back-up scheme where backing up small XMP files could be more efficient than the image and XMP as happens when Metadata is embedded.  I don't use dedicated backup software and instead just copy my full image file system (or the most recent part I'm working with) to external hard-drives using IM or Explorer. 

[JohnZeman]

I switched from processing Canon CR2 raw files to DNG about 5 years ago.  My reason for doing so was because the cameras I had at the time wouldn't generate full sized jpg preview images whereas converting to DNGs could.  And I haven't had any issues using DNGs since then but then again my image processing software programs are primarily Lightroom and Photoshop.

Now days I use Lightroom to import the files as DNGs directly from the card.  And then once I've backed up those DNGs to a second drive, I reformat the cards, which of course destroys the Canon originals.

[Carlo Didier]

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 "develeopped" preview if you use ACR (Bridge or Lightroom). One format for all images, even after having changed cameras several times.

Disadvantages? The only one I see is concerning backups: if you change metadata in a DNG, simple backup software will re-backup the whole DNG (smarter backup software is block based, but that's another story). As I normally don't change in-file metadata after the images are indexed in iMatch (all the additional metadata, like categories, is only in iMatch), and as my backup software is smart enough, this is not a real problem for me.

This has been working fine for me for several years. Never had any problem with it.

As for DxO, in my opinion, they are simple stubborn in not accepting DNGs as input format, except for camera native DNGs. Even a "converted" DNG still contains the original raw image information (without using the option to embed the original raw file!), as DNG is essentially just a container format. The raw information is just losslessly compressed, as if it were zipped. DxO is closing their business to lots of users by their stupidity (they acknowledged to me that there was no technical reason behind this!).