On Apr 3, 6:42 pm, "=\(8\)" wrote:
I can only tell you what Thomas Knoll, Chris Cox, etc. have said on the Adobe forums over the last year or so. A lot of people and a lot of talk has went on about what you loose if anything when converting to DNG and it has been made clear by both Chris and Thomas that not everything makes it over. If Adobe can’t figure out how to break the encryption they can’t do anything with the data.
There are two different things being mixed up there. "Can the DNG Converter copy the data from the original raw file to the DNG file?" And "can Adobe products make use of the data?"
The DNG Converter copies across a lot of metadata (typically in Makernotes) that it doesn’t understand and that Adobe software doesn’t use. It does so in case other products know what to do with it. I have been tracking what Adobe people have been saying in forums over the last year or two, at:
http://www.barrypearson.co.uk/articles/dng/safety.htm#comple teness The format it uses to store it in the DNG file is as follows:
http://www.barrypearson.co.uk/articles/dng/specification.htm #dngprivatedata [snip]
As for the SDK it isn’t a complete SDK they are still keeping things hidden and that means that if Adobe can’t figure it out in a reasonable amount of time then it won’t get transferred.
Data in the Makernote will get transferred to the DNG file if the Makernote is well-formed, because Adobe has the information needed to transfer it without needing to understand its content. It is only if there are complications such as references from the Makernote to data outside the Makernote string that the DNG Converter is likely to miss it. This happened (perhaps still does) with some ORF data, but for Canon, Nikon, PEF, etc, Adobe believe they copy the whole of the Makernote and related data.
[snip]
1. If something in a RAW file is encrypted it won’t get transfered.
It can and will get transfered if it is simply part of the Makernote string. Since Adobe doesn’t understand much of the Makernote data that is copied across to the DNG file, it doesn’t even know whether much of it is encrypted.
2. Adobe doesn’t list the camera models that have RAW files with information that doesn’t get transfered.
They have mentioned them in forums and elsewhere. See the link above to my page. For example, after the statement that Canon and Nikon Makernotes were copied across, I asked Thomas Knoll in an Adobe forum about PEFs, and he said the PEF Makernote is copied across:
http://adobe.groupbrowser.com/t12649.html 3. Because of 1 and 2 above we have no idea if all of the data in our cameras native raw files are getting transfered over when we convert them to DNG. Without Adobe telling us that this camera doesn’t have this transfered becuase it is encrypted we will never know and Adobe doesn’t seem to want to do that.
I want Adobe to document those things. But they have documented much of it, although in a fragmented way. That is why I maintain references to the fragments in my link above.
4. Is 1, 2, or 3 above likely to present a large problem is the grand scheme of things? Probably not, but until 3 above happens we have no way of knowing for sure. So unless you have a very drastic need for DNG I wouldn’t convert.
[snip]
What do you think is being lost? Something that make you pictures into prize-winners? In fact, for all cases I’ve tried (which is lots), if you use Adobe software for raw conversion, it makes no difference whatsoever to the final image whether you go via DNG or not. The test I use for this is documented at the following, and anyone with concerns can do the test for their choice of raw converter:
http://www.barrypearson.co.uk/articles/dng/safety.htm#softwa re It isn’t a matter of "drastic need". It is up to people to decide whether the benefits are sufficient to balance any perceived disadvantages. For me they are, (and in fact I don’t really see disadvantages), and I have been using DNG for years.
http://www.barrypearson.co.uk/articles/dng/benefits.htm —
Barry Pearson
http://www.barrypearson.co.uk/photography/