Are IFD0 fields always about the primary image, and IDD1 about the thumbnail?
Families I've seen....
IFD0
IFD1
IFD2
SubIFD
EXIFIFD
InteropIFD
etc. I think I've seen SubIFD1, maybe 2...
I can't say that the EXIF spec really helped me interpret these families and their meaning! Any help would be sincerely appreciated. : )
- J
For JPEG images, IFD1 is the thumbnail.
For other types (TIFF, DNG, RAW), IFD1 may store other things.
- Phil