On Thu, May 04, 2006 at 11:40:02AM -0400, Mark Erickson wrote:
> All,
>
> I think that this has been beaten to death already, but can someone who
> knows summarize exactly what metadata gets lost when a files is converted
> from Pentax Raw to Adobe DNG?
>
> Thanks,
>
> Mark
Short answer(1): The lens ID code.
Short answer(2): Nothing.
If you select the appropriate settings for DNG, the Pentax private data
in the MakerNote tag will get copied to the DNG file, so no information
is lost. The real problem is that there is no standard EXIF tag scheme
to identify the lens. This means that to get at that information, a
program must either:
o Know how to find the information in the .PEF
This is what the Pentax browser and Photo Laboratory do.
That's why they can show you the name of the lens you used.
or
o Know how to find the information in the copy of the MakerNote
tag, and/or in other non-EXIF tags created during RAW conversion.
While the information isn't lost, that doesn't help you all that much
if you don't have software that can extract the information. But at
least it would be possible to put together a little utility to extract
the lens ID code, and translate it to the appropriate lens nae string.
