Modifying XMP values only partially recognized by other programs
Added by Damon Lynch almost 10 years ago
This is not a problem with exiv2, but I figure here would be as good a place as any to ask this question: is it quixotic to hope that modifying Exif values in a RAW file's XMP sidecar will be consistently picked up by other programs? For instance, using the values found in a CR2's XMP sidecar, Adobe Bridge CS5 correctly overrides the actual CR2's exif:FNumber but appears to ignore sidecar's exif:FocalLength. (Making identical changes to the EXIF values in JPEG files works fine).
The reason I'm asking is that I am hoping that I can insert sensible focal length and aperture information for RAW files created with fully manual lenses (i.e. those with no computer chip). On my Canon, the aperture is set to 0.0 and the focal length to 50mm.
Of course if it doesn't work using RAW + XMP, the alternative solution is to modify the TIFFs / JPEGs created after raw processing. This is ok, but hardly ideal.
Replies (2)
RE: Modifying XMP values only partially recognized by other programs - Added by Andreas Huggel almost 10 years ago
Hi Damon,
In my opinion, the fiddling answer to your question is yes. It's unlikely that each program that deals with XMP metadata and sidecars implements this consistently, despite the existence of the Metadata Working Group which provides guidelines for some of this.
Andreas
RE: Modifying XMP values only partially recognized by other programs - Added by Damon Lynch almost 10 years ago
Hi Andreas,
After reading through their documentation, I see I was mistaken in my assumption that Exif metadata in an XMP sidecar should override that found in the image. It seems the Exif values in the image itself always have precedence. Thanks for the link!
Damon