[Originally posted by jhdiii on 2007-04-14 04:31:58-07]
Attempting to write some tags gives me results like this:
$ exiftool -v5 -maxaperture=2 01.jpg
Writing MIE-Lens:MaxAperture
Writing Minolta:MaxAperture if tag exists
Writing Canon:MaxAperture if tag exists
======== 01.jpg
Rewriting 01.jpg...
Editing tags in: APP0 APP1 CIFF ExifIFD IFD0 JFIF MIE-Lens MakerNotes
Creating tags in: MIE-Lens
JPEG APP0 (14 bytes):
0000: 4a 46 49 46 00 01 01 00 00 01 00 01 00 00 [JFIF..........]
Rewriting JFIF
JPEG APP1 (214 bytes):
0000: 45 78 69 66 00 00 4d 4d 00 2a 00 00 00 08 00 05 [Exif..MM.*......]
0010: 01 1a 00 05 00 00 00 01 00 00 00 4a 01 1b 00 05 [...........J....]
0020: 00 00 00 01 00 00 00 52 01 28 00 03 00 00 00 01 [.......R.(......]
0030: 00 01 00 00 02 13 00 03 00 00 00 01 00 01 00 00 [................]
0040: 87 69 00 04 00 00 00 01 00 00 00 5a 00 00 00 00 [.i.........Z....]
0050: 00 00 00 01 00 00 00 01 00 00 00 01 00 00 00 01 [................]
0060: 00 08 82 9a 00 05 00 00 00 01 00 00 00 c0 82 9d [................]
0070: 00 05 00 00 00 01 00 00 00 c8 88 27 00 03 00 00 [...........'....]
0080: 00 01 19 00 00 00 90 00 00 07 00 00 00 04 30 32 [..............02]
0090: 32 30 91 01 00 07 00 00 00 04 01 02 03 00 a0 00 [20..............]
00a0: 00 07 00 00 00 04 30 31 30 30 a0 01 00 03 00 00 [......0100......]
00b0: 00 01 ff ff 00 00 a4 02 00 03 00 00 00 01 00 01 [................]
00c0: 00 00 00 00 00 00 00 00 00 01 00 00 00 07 00 00 [................]
00d0: 00 20 00 00 00 01 [. ....]
Rewriting IFD0
Rewriting ExifIFD
JPEG COM (72 bytes):
JPEG DQT (65 bytes):
JPEG DQT (65 bytes):
JPEG SOF0:
JPEG DHT (29 bytes):
JPEG DHT (179 bytes):
JPEG DHT (29 bytes):
JPEG DHT (179 bytes):
JPEG SOS
0 image files updated
1 image files unchanged
The file is not written to. What am I missing?
[Originally posted by exiftool on 2007-04-14 11:57:25-07]
The MaxAperture tag you are trying to write is only defined in the
makernotes of some digital cameras (Canon and Minolta), and in
the MIE file format. Nothing is written here because this image isn't
from either of those cameras, and isn't a MIE file.
Makernote tags can not be added or deleted, only edited. So unless
the image already contains a MaxAperture tag, you can't write it.
I know this doesn't help much, but hopefully now you understand the
reason.
- Phil
[Originally posted by jhdiii on 2007-04-14 17:54:24-07]
I see - thank you! Are makernote tags not addable by definition, or by exiftool specifically? If the latter, do you know of any utilities that could create a Canon makernote tag? It would be worth my while to do a two-step process of creating with one utility and then editing with exiftool. My situation is that I have 10 years of data stored by Canon Technical Back E's, which recorded parameters for EOS 6xx film bodies. I'm now scanning the slides. I've written a converter from TBE dumpfile to exiftool command line, and it would be nice to get all of the data into the Exif files. Though sold ca. 1990, the Canon-specific part of the data it produces maps perfectly to the available values for Canon:MaxAperture, Canon:FlashBits, CanonExposureMode, and Canon:MeteringMode.
Since the image files are created by scanner/editor, there is no makernote.
John
[Originally posted by exiftool on 2007-04-14 19:20:36-07]
Hi John,
To my knowledge (anybody who knows otherwise, feel free to correct
me:), exiftool is the only utility that exists with the ability to write maker
notes. Nobody else is crazy enough to attempt this.
I don't allow you to add/delete individual makernote tags for a reason:
The makernotes are proprietary and without a written specification there
is no way to tell if any given tag is required.
You could use exiftool to copy the entire canon makernote (plus the
Make and Model tags!) from a file from another camera, but I don't think
this is what you want to do because then you get a bunch of other
unrelated information too.
The only extensible, portable and popular metadata format is XMP. I
would suggest defining a set of tags in XMP to do what you want. Look
at the ExifTool_config file included with the distribution for an example
of how to create user-defined XMP tags. This way, you can add any
tags you want in a way that will be most compatible with future
utilities down the road.
- Phil
[Originally posted by jhdiii on 2007-04-15 16:02:35-07]
OK, thanks. And thanks for exiftool!