Bottom line - DNG working or not

I have had success importing DNGs, for my 1DS mkII and Digital Rebel XT. All metadata is stripped, but the image is fine and not restricted to a JPEG thumbnail as you described.
I did not have success importing DNGs from my pocket camera, a Powershot S50. Those acted as you described.
I started another discussion about importing images:
http://discussions.apple.com/thread.jspa?threadID=254204&tstart=0

dual g5 2ghz Mac OS X (10.4.3)

dual g5 2ghz Mac OS X (10.4.3)

Well, speaking for myself, I can't get any DNG image to import to Aperture successfully. After import the image thumbnails are grayed out and when selected I receive a message saying "Image format not supported".

In going through the Getting Started book that came with Aperture, I am realizing that DNG is not listed among the supported file formats.

Is anyone having luck with DNG imports?

I've just found the same issue. DNG files created from a LEICA Digilux 2 are not supported in Aperture but DNG files from a Nikon D2H are supported.

I truly hope this is a bug!

Apparently Apple, (and several other vendors) have not completely implemented their DNG readers. Here is a discussion on the Adobe web site you might find interesting:
http://www.adobeforums.com/cgi-bin/webx?128@108.xIsaf6H3sC8.10@.3bbd1094

dual g5 2ghz Mac OS X (10.4.3)

DNG files coming directly from a camera are "supported", converted files are not. I was told that this is being addressed and that the Aperture specs on the Apple site will be updated.
I like the program and I want to love it but they have some work to do make it function as it should. It is a lot to ask to change your workflow completely and run everything through Aperture.
I don't know how many professional photographers they collaborated with when creating this but they obviously should have spoken with a few more...

That thread on the Adobe forum does not seem conclusive to me, though it's been posted to several here. If you read more of Adobe's documentation on DNG, it seems that unless you use the linear conversion feature, then you are relying on any other app's ability to specifically support the camera. Frankly I'm still confused, but I'm starting to think that this DNG compatibility has limits based on the preferences that you choose in DNG Converter. To copy what I said on another thread:

look at the Prefernces inside DNG Converter and read what they say. If you select "Convert to Linear Image," it says:


"The image data is stored in an interpolated ("demosaiced") format. This can be useful if a camera's particular mosaic pattern is not supported by your DNG reader." (emphasis added)

I haven't really messed with this, but it seems like the only really valid and useful way to deal with DNG would be to "convert to linear image" AND "Embed Original Raw File." ... otherwise, it would seem that you are not gaining any compatibility advantage, because you're still relying on camera specific support. I don't think the DNG documentation is nearly explicit enough on this. I've just read the PDF titled "Introducing the Digital Negative Specification," and it does not elucidate this... Of course doing it the way I suggest has two disadvantages: double the file size (but let's ignore that, since the priority is being arcvhival) and also a potential decrease in quality by going to linear prematurely.... the truly best way would be something that DNG Converter does not offer: If you really wanted the utmost in archival, it seems you would take triple the file size hit and do the file three ways: "Preserve Raw Image," "Convert to Linear Image," and "Embed Original Raw File" all at the same time... then you would make it part of the standard for DNG-supporting readers to prefer them in that same order automatically. Am I thinking clearly?


of course I'm totally new to DNG, and I want my position to be attacked with more useful details from others who are digging into this...


G5 dual 2.0

If a camera is supported, then DNG buys you nothing? A converted DNG file from an unsupported camera would be hugely useful, but doesn't seem to be even a remote possibility.

The Aperture marketing material definately gave the impression that supporting DNG extended the usefulness of the product. As far as I can see, it is a complete irrelevance.

Just a me too post: .DNGs converted from .CR2 sourced from a Canon 20D also come out at 256x171... very frustrating. Preview.app also renders them like this.

I've seen rumors that the upcoming 10.4.4 update may bring with it improved RAW support: my fingers are crossed.

.DNG from some supported cameras doesn't work either - see my reply regarding the Canon 20D.

Jack,
The point of the Adobe post is that a DNG file reader, such as ACR 2.4, if properly implemented, can READ DNG files from a camera that was not anticipated when the software was written - thus Adobe's claim to a more robust archival format.
There are three sources of confusion:
1. ACR 2.4 can't READ RAW files from an unanticipated camera, but it can READ DNG from the same camera.
2. I have observed the linear option on RAW conversion, but this is a red herring. ACR 2.4 is reading uninterpolated DNG files from unanticipated cameras.
3. Apple's implementation of DNG DOES NOT allow it to READ DNG files of cameras whose RAW files it doesn't support. My guess is that they rushed to add it and therefore hamstrung their implementation. If Apple would address this issue we could all happily convert our unsupported RAW files to DNG. Then of course if they would import embedded IPTC metadata from the DNG files we'd really be cooking.

Jeff

PS. I tried the linear option on some RAW Powershot S50 files I have, and Aperture still couldn't manage the resulting DNGs.


dual g5 2ghz Mac OS X (10.4.3)

Buttel -

Thanks for the extra info. This DNG really is confusing. This point really gets me:

There are three sources of confusion:
1. ACR 2.4 can't READ RAW files from an unanticipated
camera, but it can READ DNG from the same camera.

... Adobe's website says that DNG Converter and ACR support the same cameras, so how would DNG Converter convert it in the first place if ACR could not read it? It's possible that Adobe has added cameras to DNG Converter that are not in ACR without updating that statement, but as it reads, that statement is not helping me 😀

- Jack

G5 dual 2.0

Jack-
DNG files treat raw data from image sensors in a consistent fashion. Camera manufacturers have not felt any need to treat raw data consistently. Therefore each manufacturer is free to (and does) create a new format each camera's RAW file, even though the information needed to convert the raw image data into TIFF, PSD, or JPEG is not all that different.

So what happens now when a new camera is introduced is that all the software houses that handle RAW files race to create converters specifically for that format. And photographers wait for Adobe (not too patiently) to update ACR to handle their hot new cameras. And those with older versions of Photoshop wait for the new DNG converter, which can translate the new RAW format to DNG, so that their older (ACR 2.4 for example) can read it.

Of course if the camera manufacturer introduces a new camera with DNG formatted raw files, the software houses don't have to translate, the photographers don't have to wait for Adobe to update ACR and the DNG converter.

The advantage of DNG should be that if a software house fully implements the DNG spec when reading files, it should have no trouble converting those files to a non raw format.

It also means that if you have converted your RAW files to DNG, you can feel more confident that those files will be readable on future computer systems. This is because it is much more likely that companies will invest the effort to code a single DNG converter rather than a plethora of RAW converters for any new computer systems.

I am speculating that Apple, in a rush to get Aperture to market, crippled their DNG implementation by coding to handle the specific parameters of the cameras they support, rather than coding to the general parameters in the DNG spec. If they had the time, any RAW format that the DNG converter handles currently would be supported by Aperture in DNG files. (but not necessarily the RAW files those DNG files were derived from). Too bad.

Going forward there is no guarantee that DNG will handle new imaging technologies. I don't for example know how it handles Fovean files, and there are likely to be other imaging technologies that the DNG spec doesn't anticipate. Oh well.

Anyway, I hope this is helpful. I hope I can pull my Powershot S50 RAW files into Aperture one day. I hope all the IPTC metadata embedded in all my RAW files will be read by Aperture one day. I hope I can export RAW files from Aperture intact with embedded metadata so I can perform raw operations outside of Aperture.

Good night,
Jeff

dual g5 2ghz Mac OS X (10.4.3)

As you noted, the documents around conversion seem to imply that if nothing else works you should be able to select the "Linear" option and get a demosiaced image for a program to read from your DNG file.

However, I have tried that (since my camera is not supported otherwise) and Aperture does not understand the linear RAW DNG files - or at least cannot read the images from them. This is rather unfortunate since it is supposed to be a fallback.

The downside to the linear format is that you loose the ability for a program to demosiac better than ACR did in the first place when it created the DNG... which is why (again as you pointed out) you really want to embed the original RAW file if you use this option. In reality ACR is a pretty good demosaic program and for most other programs you might actually be better off with ACR doing the demosiacing rather than Aperture, or any other program apart form professional software like C1. Indeed, if C1 were clever they would offer the option to output a really high-quality Linear DNG demosiaced image for use with programs like Aperture - C1 at the front and Aperture handling other aspects of manipulating and tagging images would be a great combo.

I figure Aperture DNG support will improve pretty rapidly since reading the linear DNG file image is actually pretty straightforward, and other uses of DNG for real raw bayer data will probably get an overhaul quickly. But for now I would say support for DNG is indeed minimal at best.


Powermac G5 1.8GHz DP Mac OS X (10.4.3) Radeon 9800 Pro Mac Special Edition, dual monitors