I don't usually do manuals, but I do occasionally read the update notes. I realized I have to change the preferences to an earlier version of the DNG converter.
Good that you established the reason for the problem and reporting back to the forum.
Do you have any idea why the older converter creates such large files, but the newer converted files are much smaller? Any chance this will change in the future or is upgrading to CS4 the only option? BTW, I am converting RW2 files from a Panasonic LX3.
In the case of your Panasonic files the older converter creates linear demosaiced files whereas the new converter when configured to create CR 5.4 and later DNG files doesn't need to demosaic the original files. Edit: However, you can configure the new converter to create the larger files, which will be readable in CS2 (see attached screen shot of DNG Converter Preferences).
The behaviour you're seeing is specific to a small subset of the cameras supported by Camera Raw / Lightroom. Unfortunately, this behaviour will remain the norm for such cameras. So, yes you will need to upgrade to CS4 and ACR 5.4 or later to benefit from the smaller DNG files.
I expect that Eric or Thomas will provide a more comprehensive explanation at some point.
The raw data of several Panasonic cameras did not fit to the imagination of the DNG designers (so much to the universality of DNG). Therefor the raw data had to be converted in "linear" format. In this format each pixel has three values, as opposed to the original, Bayer type data. Thus the original data amount become tripled.
The brand-new DNG specification has been expanded, the Panasonic raw data is described by a new tag, but that can not be interpreted by the old raw processors.
The raw data of several Panasonic cameras did not fit to the imagination of the DNG designers (so much to the universality of DNG).
That is incorrect.
Eric, I am ready to backtrack my statement if you can show, that DNG 1.2 is sufficient for the proper processing of those Panasonic images and the new tag is not a requirement (but then I would not understand, why the images could not be converted in mosaic DNG with 1.2).
I am keenly waiting for the release of the 1.3 specification to see, what is in the new tag.
Panoholic, it has been reported that the latest Panasonic cameras rely on post-processing to correct for geometric distortion. If that's the case, `straight' raw conversions will be close to useless for most applications. Since geometric corrections were probably on the ACR team's to-do list anyway, I wouldn't be surprised if these are the new extensions making their way into DNG 1.3.
So, yes, a `proper' interpretation of Panasonic raw files would require the new specification. However, it goes a bit far to state that this "did not fit to the imagination of the DNG designers". Most likely they thought of this before, but didn't want to bog down the specification with (at that moment) unnecessary details. It's often better to wait with the details of the implementation until you know what you actually need it for.
Now, let's hope we (the ACR/Lightroom users) get an interface for the geometric corrections.
To clarify my earlier (admittedly brief and not very helpful) post, we must be careful to distinguish between the raw image data itself and the (possibly required) processing of that image data. The raw mosaic image data itself from a .RW2 is certainly compatible with earlier DNG versions (e.g., 1.1, 1.2). However, the reason that earlier versions of Camera Raw create linear DNGs, instead of mosaic DNGs, is given in Tom Hogarty's CR 5.2 release notes:
To quote the relevant section directly:
This exception is a temporary solution to ensure that Panasonic and Leica's intended image rendering from their proprietary raw file format is applied to an image when converted DNG files are viewed in third party software titles. The same image rendering process is applied automatically in Camera Raw 5.2 and in Lightroon 2.2 when viewing the original proprietary raw file format.
In a future release Adobe plans to update the DNG specification to include an option to embed metadata-based representations of the lens compensations in the DNG file, allowing a mosaic DNG conversion.
We can debate what level of processing is required to obtain an acceptable image.
However, the original claim -- stating that "The raw data of several Panasonic cameras did not fit to the imagination of the DNG designers" and then concluding that this is the reason that "the raw data had to be converted in 'linear' format" -- is incorrect.
I do concede, that no-one could have dreamed of the extentions required for the Panasonic raw data years ahead. I did not mean that as a "personal critique", rather a critique of the concept: the DNG specification is not generic enough and it can not be generic enough, just as this example shows (this is not the first example).
On the other hand, I find your remark somewhat intriguing:
we must be careful to distinguish between the raw image data itself and the (possibly required) processing of that image data
The DNG specification has always been a mix-up between the interpretation of the raw data and its rendering. The original DNG specification did not cover the processing aspect. It still does not cover so trivial issues, as contrast, sharpness, saturation (forget about the worthless Exif tags), but now it includes color profiles, curves, and even the correction of lens geometric distortions.
I have the feeling, that the incorporation of these aspects (i.e. those relating to the rendering) does more damage to DNG than any new, in DNG not specified hardware feature could do.