[mike.strock]

I converted some of my CRW/THM combination files to DNG to see what they'd be like in BBPro 1.7beta. I guess I misunderstood, as I thought that the RAW conversion utilities would be available for these DNG files.

But it appears (at least to my untrained eye) that DNG is just a JPG type file format, as far as BBPro is concerned with regards to RAW conversion.

Is this true? Does this email make any sense at all?

I thought I could convert the CRW/THM files to a DNG and then still use the RAW conversion utilities of BBPro to convert it to JPG or TIF or whatever....

Am I mistaken? Am I missing the boat here?

Thanks!

Mike
[email protected]

[DavidB]

I converted some of my CRW/THM combination files to DNG to see what they'd be like in BBPro 1.7beta. I guess I misunderstood, as I thought that the RAW conversion utilities would be available for these DNG files.
BB Pro can read DNG, but not convert it. For reasons, read on ...


But it appears (at least to my untrained eye) that DNG is just a JPG type file format, as far as BBPro is concerned with regards to RAW conversion.
DNG is more like RAW than JPEG; it is in fact Adobe's 'Digital Negative' format, which Adobe hoped (still hopes?) would replace proprietary RAW formats. As far as I know, all major camera manufacturers have given the idea the cold shoulder, and DNG has become an open standard archiving format with the essential characteristics of a RAW file. For a supporter's view see this link (http://www.luminous-landscape.com/reviews/software/dng.shtml). But that was written in 2004. Since then, so far as I know, none of the independent RAW conversion programs (e.g. C1, Bibble) has supported DNG.


I thought I could convert the CRW/THM files to a DNG and then still use the RAW conversion utilities of BBPro to convert it to JPG or TIF or whatever....
I'm afraid not. For Canon RAW conversion, BB Pro uses Canon's RAW conversion libraries, and there is no chance that they will offer a conversion to or from DNG anytime soon. Indeed the only converter I know (in either direction) is the Adobe plug-in, which is typically used by Photoshop (and, I assume, Lightroom), but for which there is a stand-alone front end executable. DL Pro also provides a plug-in which is, essentially a link to the Adobe software, and which enables you to generate DNGs of your RAW files on download. You can also use the BB Pro link to an editor (Ctrl+D) to open DNG files in Photoshop or Elements, which I think is as close as you can get to what you were trying to achieve.

Personally, I think DNG was and is a good idea. It's just a pity that Adobe had it. But there you go.

[mike.strock]

Thanks for the great reply David. Essentially, from what I've read of your reply, DNG is Adobe's Walled Garden.

It's not really a walled garden, where no one else can come in. It's a walled garden in the sense that Adobe will let folks in, but folks don't want to come in.

Very sad. So in order to use DNG (which does seem to cut down on file size in my testing if I don't put the RAW file inside), I have to use either Lightroom or Photoshop. That really is a conundrum.

Thanks again.

Mike Strock
[email protected]

[Chris Breeze]

BBPro uses Canon's raw conversion libraries to convert Canon raw files and these work with CR2, CRW and the original 1D series TIF raw files. The Canon libraries produce excellent results but they do not support DNG raw conversion.
In time DNG may become the new universal raw format but I don't think this will happen until the major companies (e.g. Canon and Nikon) use it in their cameras.
At the moment converting existing raw files to DNG will limit your choice of raw converter. All the major raw converters support Canon CRW, CR2 and TIF raw files, Nikon NEFs etc. whereas only a handful support DNG conversion.

[Barry Pearson]

DNG is more like RAW than JPEG; it is in fact Adobe's 'Digital Negative' format, which Adobe hoped (still hopes?) would replace proprietary RAW formats.... But that was written in 2004. Since then, so far as I know, none of the independent RAW conversion programs (e.g. C1, Bibble) has supported DNG.

I'll comment below on this.


In time DNG may become the new universal raw format but I don't think this will happen until the major companies (e.g. Canon and Nikon) use it in their cameras.
At the moment converting existing raw files to DNG will limit your choice of raw converter. All the major raw converters support Canon CRW, CR2 and TIF raw files, Nikon NEFs etc. whereas only a handful support DNG conversion.

1. Whether Nikon and Canon support DNG in-camera is one of the least important aspects of DNG. Most photographers with a DNG-based workflow use Nikon or Canon. Most DNG-based raw images started in Nikon or Canon cameras. (I use a Pentax K10D which offers the choice of PEF or DNG. I use PEF - because the Epson P2000 can display PEFs, and because the K10D doesn't use DNG's lossless compression. This choice simply doesn't matter to me - I convert while downloading to the PC, and see only DNGs).

2. What matters far more is support in software rather than cameras. The basic list of software products that don't support DNG is: "the large majority of products supplied by camera manufacturers, plus a few others, of which Bibble and Capture One were probably the only important ones". Capture One plans to support it later this year in v4.

There are more than 160 non-Adobe products that support DNG in some way, from more than 150 sources. My estimate is that until Capture One supports DNG, most raw shooters, (perhaps 55% - 60%), sometimes or always use software products that don't accept DNG. When Capture One supports it, that will probably become a minority. (I'm using the OpenRAW survey from the start of last year).

Yes, many raw shooters are excluded because of their choice of software. But many photographers have been using DNG successfully for years. Whether particular photographers can get any benefit from DNG depends on their workflow and the tools they use. (The situation gradually improves over time). Not everyone can get immediate benefit yet, or enough benefit to counter any perceived disadvantages.

The following pages are intended to help photographers make their own informed decisions:
http://www.barrypearson.co.uk/articles/dng/benefits.htm
http://www.barrypearson.co.uk/articles/dng/products.htm
http://www.barrypearson.co.uk/articles/dng/not_yet.htm

[Chris Breeze]

But what is the point of converting from the Canon or Nikon raw formats to DNG? All raw converters that can convert the DNG files can also convert the native raw files and so what have you gained?

There is always a risk that some data is lost when converting from one format to another. The early versions of Adobe's DNG converter discarded the Canon MakerNote and so you lost much of the detailed camera specific shooting data. The latest versions of the DNG converter do keep the MakerNote now but very few apps can read it (BBPro can but I don't know of any other apps that read it).

Some cameras do shoot DNG natively and some like the Pentax K10D give the option of shooting DNG or PEF. One major disadvantage of shooting DNG in camera is that they don't make full use of the DNG file format and only store the raw data and the thumbnail. This means there is no large preview JPEG available for quickly browsing images. Almost all cameras shooting proprietory raw formats store a large JPEG preview image in the raw file (including the K10D when shooting PEF raw files). Adobe's DNG converter stores the raw data, a thumbnail and a JPEG preview image.

[DavidB]

First of all, grateful thanks to Barry both for his post, and for putting together all the information on his site. It is good to see that so many applications support DNG in some way, so the process of 'seepage' is clearly happening. But, as I think Barry agrees, we are not at critical mass just yet.

Chris asks:

But what is the point of converting from the Canon or Nikon raw formats to DNG? All raw converters that can convert the DNG files can also convert the native raw files and so what have you gained?
My answer is that DNG is the only standard which can claim to offer both the advantages of RAW and (if it achieves critical mass) long-term future-proofing. Once a particular format (digital or physical) drops out of favour, support is only available in niche markets, and typically at a price. 120 film is a good example. Camera-specific RAW formats will go that way one day; the only question is when.

The other point about genuinely open standards is that they are empowering. I don't think that digital photography would have taken off as it did if the JPEG standard had not been in place, so that users could, almost from the outset share images quickly and freely. I can send a JPEG knowing that the recipient will have some means of reading it; that is not true of my .cr2 files.

PDF is an example of a standard that has come out from under Adobe's wing and is now genuinely open. I am one of those who want to see DNG go the same way, and I agree with Barry that, if C1 starts to support it, that will be an important milestone. However, 'support' in this case needs to include conversion both to and from DNG; in that respect it differs from both RAW and JPEG.


There is always a risk that some data is lost when converting from one format to another.
I think that this compresses the argument too much. Data loss can arise either because the receiving format is inherently 'lossy' (like JPEG, but unlike DNG), or because the conversion is badly implemented (i.e. not in accordance with the standard). Unless the standard is inherently difficult to implement, a bad implementation does not justify criticism of the standard as such. Chris's examples are both, by definition, bad implementations.


. Whether Nikon and Canon support DNG in-camera is one of the least important aspects of DNG. ... What matters far more is support in software rather than cameras.
I am about 80% in agreement with this. But

DNG conversion from RAW is, as Chris says, another step in the workflow (albeit that it can be automated in DL Pro); if you want DNG, getting it direct from the camera would be nice;
the very fact that major camera makers have to be dragged kicking and screaming into support for open standards means that, if they ever adopt them, those standards have definitely reached critical mass;
the availability of out-of-camera DNG would call into question the need for proprietary RAW formats (Chris's argument turned on its head), and perhaps we will have a time when software writers are not forever struggling to keep up with the generation of new, camera-specific formats;
DNG support in the Canon libraries would mean that BB Pro supports conversion from (and perhaps to) DNG, at least for my cameras :) .



P.S. Leaving aside the obvious commercial and intellectual property issues, is there any good technical reason why each new DSLR model has to have its own RAW format? This is an enquiry, not an expression of opinion; I genuinely don't know the answer to the question.

[DAustin]

This is certainly an interesting discussion by well-spoken people. I doubt that I'm up to the same quality of contribution, but I wanted to offer one point I didn't see mentioned: DNG permits open and secure embedding of XMP metadata. This fact by itself seems to have driven a lot of folks to adopt DNG in their workflow.