At 02:33 PM 7/5/2005, you wrote:
This certainly isn't the way it appears when I open it. The .dng file
appears exactly the same as the Canon RAW file and has the same control
over white balance and colors. I don't know what the underlying structure
is, but from a user's point of view rather than a technologist, it is
identical.
Jeff Spirer
I agree, Jeff. It's way too complicated for me. I've tried to read
Adobe's specifications on DNG and it sounds like Greek!
http://www.adobe.com/products/dng/pdfs/dng_spec.pdf
I've been depending on the experts to translate it and this is what the
experts say on the OpenRaw.org site:
"Currently the Adobe DNG format does not meet the goal of OpenRAW. At this
time (May 18th, 2005) no available cameras write DNG format files. To use
DNG files, existing RAW formats need to be converted. Unfortunately, since
most current RAW formats are not fully documented, the conversion from RAW
to DNG is still based on reverse engineering of undocumented metadata
(tags). Therefore it is possible to misinterpret or lose critical
information. Billions of existing RAW images have already been archived.
Only open documentation of past and existing RAW formats can ensure full
utilization of these archived RAW files.
DNG also allows "private data" to be stored in the DNG file. This private
data is only known to the camera company that wrote the private data. Third
party software that reads and/or writes DNG files will ignore private data
recorded by the camera. Only the software written by the camera maker will
read the private data written to the DNG file by its camera. Some of this
private data might be important or useful information needed by a RAW
converter. Adobe's DNG format does not eliminate the problem of
undocumented RAW files but transfers the problem into another "container",
the DNG file. By allowing private (undocumented) data in the DNG file, DNG
does not meet OpenRAW's goals."
It was in discussing the only camera that now uses DNG as their RAW, the
new Leica Digital back, that the experts said that DNG is really a TIFF and
doesn't allow access to the unconverted white balance space.
Tina
Tina Manley, ASMP
www.tinamanley.com
