Nikon ExposureBracketValue with D3000/D3100 NEFs and JPGs

[guyy]

With Nikon D3000 and D3100 the tag for ExposureBracketValue is stored with an offset of 0
  $tagID == 25
  $format == 10
  $count == 1
  $size == 8
  $valuePtr == 0

on reading you get an harmless warning and ExposureBracketValue isn't shown
exiftool -g1 D3100.NEF

Code Select Expand


...
Warning                         : [minor] Suspicious MakerNotes offset for ExposureBracketValue
...


but when modifying the exif

exiftool '-Owner=John Doe' D3100.NEF
exiftool -g1 D3100.NEF

you get

Code Select Expand


Warning: [minor] Suspicious MakerNotes offset for ExposureBracketValue - D3100.NEF
    1 image files created
...
Exposure Bracket Value          : +162113114
...


Nikon ViewNX 2 drops that tag in modified D3100 NEFs.

The D3000 and D3100 samples on imaging-resource.com can be used for testing.

OS: FreeBSD 8.1
exiftool version: 8.40

Regards,
Guy

[Phil Harvey]

Hi Guy,

Yes, thanks.  I was aware of this "feature" of the D3100 images.  It is not uncommon for a camera to write dummy entries in the makernote IFD, but usually the format would be set to zero causing it to be ignored.  It is unfortunate that they chose to just set the offset to zero, because it is common for the maker note offsets to be corrupted so they can't be tested reliably.  The only option would be to add yet another special-case patch for this, but I don't think it is worthwhile in this case.

Instead, it would be better if Nikon hired smarter software engineers.

- Phil