an ExifOffset calculation question

[qdwang]

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......
  | 9)  ExifOffset (SubDirectory) -->
  |     - Tag 0x8769 (4 bytes, int32u[1]):
  |         008a: ae 02 00 00                                     [....]
  | + [ExifIFD directory with 42 entries]
  | | 0)  ExposureTime = 0.002 (10/5000)
  | |     - Tag 0x829a (8 bytes, rational64u[1]):
  | |         04c4: 0a 00 00 00 88 13 00 00                         [........]
......


I tried to use exiftool -v3 to parse an Panasonic RW2, but don't know how the Offset calculation works.

Since 0x008a + 4 + 0x02ae does not equal to 0x04c4, how the 0x04c4 offset is calculated?

Thanks.

[Phil Harvey]

The ExifIFD directory itself should be at 0x2ae plus the offset of the start of the TIFF information.  The value of the ExposureTime tag is stored outside the ExifIFD at a location referenced by its entry in the ExifIFD.  Maybe this will make more sense if you look at the -htmldump output.

- Phil

[qdwang]

Thanks for the reply.

Now I can get the correct result.