DNG files. Problems ?

Dear members:

In a discussion thread on one of Apple's forum on the new product Aperture some posters reported having problems with DNG files and that they didn't feel safe committing their digital raw files to this new file specification. Some felt that converting to DNG and erasing the original raw files was a risky proposition since the new standard could either have bugs or fail to receive support and end up being dropped.

Have any of you converted your images to DNG ? In case you have, what have been your experiences with DNG and what do you think about it in terms of security of your original raw files ?

Thank you and best regards,

Joseph

---

Dr. Joseph Chamberlain
Oral and Maxillofacial Surgery

Joseph Chamberlain, DDS wrote:
[snip]

Have any of you converted your images to DNG ? In case you have, what have been your experiences with DNG and what do you think about it in terms of security of your original raw files ?

[snip]

I'll repeat the response I gave to your identical question in the Adobe forums:

Most of the "fear, uncertainty, doubt" that I see about DNG in forums arises from inexperience with it, or lack of some significant information. (Some of the FUD can be attributed to people with responsibility for, or an allegience to, products that either don't support it at all, or do so only in a limited way).

People need to be comfortable with their workflow. I don't think people who keep their original raw files can be criticised. There are probably some formats where some data is not preserved in the DNG file. Adobe don't appear to have published suitable reference material on this. What there is tends to be relatively brief statements from Thomas Knoll, etc. When DNG was launched, Adobe recommended people to keep their original raws. I haven't seen that advice officially withdrawn, and doing so might invite product liability problems. Software from camera makers mostly doesn't support it, so if people want to be able to use that, they must keep the original raw files.

DNG isn't really "new" any longer. It was launched more than 14 months ago. The specification is on the 2nd version. ACR-for-DNG and the DNG Converter are on the about the 5th version (assuming you don't count
3.0). There are perhaps 80+ non-Adobe products that support DNG in some
manner:
http://www.barry.pearson.name/articles/dng/

Month-by-month, the world becomes a more "DNG-friendly" place, with more people using it, more products supporting it, more endorsements and recommendations, etc. And I doubt that Adobe has stopped adding useful features to its support!

Adobe couldn't drop support for DNG and remain in the raw processing business. Many photographers wouldn't upgrade to a version of their Adobe products that dropped DNG, because so many of their photographs and the settings and other metadata within them depend on DNG. Many of those photographers are opinion leaders. It would seriously damage Adobe's credibility. (But why would Adobe want to do so anyway?)

(I started to use DNG nearly 14 months ago. I stopped retaining my original raw files about 6 months ago, soon after upgrading to CS2 /
3.1, which retained (apparently) all of the data from my original raw
files in the DNGs).

--
Barry Pearson
http://www.barry.pearson.name/photography/
http://www.birdsandanimals.info/

Joseph Chamberlain writes ...

Have any of you converted your images to DNG ?

I haven't and none of the couple of dozen or so photographers I hang around with have either.

I don't know if this is the view of the silent majority or the unhip minority or just my own oddball way of lQQking at things, but to me DNG seems to be mainly a solution to the possible eventual problem of RAW files not being supported by current converters. So to me there are two reasons to convert to DNG -- one is permanent (if your camera format is no longer supported by your RAW converter of choice) and two is if your camera is so new that Photoshop, Raw Essentials and/or Capture One haven't caught up yet and brought out a patch or new version to do the conversion, in which case you would either use the software that came with the camera or you would convert to DNG (if possible). Historically it takes a few weeks to a few months for the major converter programs to get up to speed on new cameras. Other than those two cases I don't see the attraction myself.

Note that even when support for a camera is dropped by a company that you still have a couple of years warning (Kodak's 14 Megapixel body for Nikon and Canon mounts is a good example, recently killed with no support past 2007 iirc), so it's a bit like dodging glaciers if you've been unlucky enough to buy a market place loser. You have time, lots of time ...

I think Barry Pearson, who is the main (or certainly the loudest) advocate of DNG on this NG, has one of the slow selling 6 Mpixel bodies from Minolta or Pentax, bodies which were about 1-2 years late getting to the market and haven't been replaced by newer, higher resolution models in the past 1-2 years either, even while Nikon and Canon have been bringing out new, improved models regularly. The future looks bleak for those brands unless they have forthcoming models that will win over market share from Canon and Nikon, which seems highly unlikely. If I had one of those models I'd be a lot more interested in DNG too but anyone with Canon and Nikon cameras will certainly have excellent RAW support for many years, so why bother with DNG right now?

some posters reported having problems with DNG files and that they didn't feel safe committing their digital raw files to this new file specification.

That would make sense to me.

Some felt that converting to DNG and erasing the original raw files was a risky proposition

I think it would be dumb to erase the originals myself ... and if you already have excellent converters for the originals then why bother converting a copy to DNG?

Bill

Bill Hilton wrote:

Joseph Chamberlain writes ...

Have any of you converted your images to DNG ?

I haven't and none of the couple of dozen or so photographers I hang around with have either.

I don't know if this is the view of the silent majority or the unhip minority or just my own oddball way of lQQking at things, but to me DNG seems to be mainly a solution to the possible eventual problem of RAW files not being supported by current converters. So to me there are two reasons to convert to DNG -- one is permanent (if your camera format is no longer supported by your RAW converter of choice) and two is if your camera is so new that Photoshop, Raw Essentials and/or Capture One haven't caught up yet and brought out a patch or new version to do the conversion, in which case you would either use the software that came with the camera or you would convert to DNG (if possible). Historically it takes a few weeks to a few months for the major converter programs to get up to speed on new cameras. Other than those two cases I don't see the attraction myself.

Note that even when support for a camera is dropped by a company that you still have a couple of years warning (Kodak's 14 Megapixel body for Nikon and Canon mounts is a good example, recently killed with no support past 2007 iirc), so it's a bit like dodging glaciers if you've been unlucky enough to buy a market place loser. You have time, lots of time ...

I think Barry Pearson, who is the main (or certainly the loudest) advocate of DNG on this NG, has one of the slow selling 6 Mpixel bodies from Minolta or Pentax, bodies which were about 1-2 years late getting to the market and haven't been replaced by newer, higher resolution models in the past 1-2 years either, even while Nikon and Canon have been bringing out new, improved models regularly. The future looks bleak for those brands unless they have forthcoming models that will win over market share from Canon and Nikon, which seems highly unlikely. If I had one of those models I'd be a lot more interested in DNG too but anyone with Canon and Nikon cameras will certainly have excellent RAW support for many years, so why bother with DNG right now?

some posters reported having problems with DNG files and that they didn't feel safe committing their digital raw files to this new file specification.

That would make sense to me.

Some felt that converting to DNG and erasing the original raw files was a risky proposition

I think it would be dumb to erase the originals myself ... and if you already have excellent converters for the originals then why bother converting a copy to DNG?

Bill

Size is also a reason to convert to DNG. After shooting a wedding, I put all the files on my computer. Then I back them all up on DVD-R disks. Since DNG files are about half the size of my RAW files, I write to the disks faster and use fewer of them.

I don't have a size issue on my hard drives, but it doesn't hurt to have them smaller.

I have had no problems with DNG format. I've never lost data. They work exactly like the original RAW file. Camera RAW doesn't seem to handle it any different.

Smaller files is a good reason for me to use DNG. So I do.

Clyde

Bill Hilton wrote:

Joseph Chamberlain writes ...

Have any of you converted your images to DNG ?

I haven't and none of the couple of dozen or so photographers I hang around with have either.

I don't know if this is the view of the silent majority or the unhip minority or just my own oddball way of lQQking at things, but to me DNG seems to be mainly a solution to the possible eventual problem of RAW files not being supported by current converters.

[snip]

1. I think the single most important reason to use a DNG-based workflow is that DNG can hold metadata of various kinds that it would not be safe or convenient to hold elsewhere. Eg. ACR edits & settings; "rights" metadata such as name, copyright info, etc; and asset management metadata such as IPTC-like keywords for the shoot and individual shots. But this won't matter to some people, or they may be happy with the Adobe database or XMP sidecar files. There aren't a lot of non-Adobe products that can handle XMP metadata within DNG files, yet; probably fewer that 10.

2. Size is important to some, not to others. It depends on the cameras: the DNG from a *istD is less than half the size, while that from a 350D is perhaps 5% smaller.

3. Having a safer archival format, with, for some cameras, a superset of the original data in, may be useful to some. (The DNG Converter, or ACR 3.x, adds camera calibration data, making the DNG file "self contained"). Holding image + metadata in a publicly-documented format is useful to some.

4. Some people use the convert-to-DNG route to handle their new cameras in CS / ACR 2.4, and avoid upgrading to CS2.

It depends on one's workflow and tools. Month by month, the world becomes a more DNG-friendly place, with more products supporting it, but if you use other products, you have to wait for another month, and so on.

--
Barry Pearson
http://www.barry.pearson.name/photography/
http://www.birdsandanimals.info/