Difference in focallength report between version 12.63 and 12.90

[JohnMoyer]

Thanks for exiftool.

The filename with the IMG_0265c.JPG was processed by Canon DPP software from IMG_0265.CR3 including cropping. IMG_0265.JPG was produced by the camera. Exif:focallength seems correct to me while Makernotes:focallength does not for use of "-focallength". This problem might have been caused by me useing "-tagsfromfile" to copy makernotes from CR3 to edited JPG.

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exiftool -s -G0:2 -ExiftoolVersion -"*focallength*" -lensmodel -ImageUniqueID ~/photos/2024Jun17/IMG_0265*   
======== /home/jrm/photos/2024Jun17/IMG_0265c.JPG
[ExifTool]      ExifToolVersion                 : 12.63
[EXIF:Camera]   FocalLength                     : 800.0 mm
[MakerNotes:Camera] MaxFocalLength              : 400 mm
[MakerNotes:Camera] MinFocalLength              : 100 mm
[Composite:Camera] FocalLength35efl             : 800.0 mm
[EXIF:Image]    LensModel                       : EF100-400mm f/4.5-5.6L IS II USM +2x III
[MakerNotes:Image] ImageUniqueID                : 0db2f09024464a4ba1b91d62c962c613
======== /home/jrm/photos/2024Jun17/IMG_0265.CR3
[ExifTool]      ExifToolVersion                 : 12.63
[EXIF:Camera]   FocalLength                     : 800.0 mm
[MakerNotes:Camera] MaxFocalLength              : 800 mm
[MakerNotes:Camera] MinFocalLength              : 200 mm
[Composite:Camera] FocalLength35efl             : 800.0 mm (35 mm equivalent: 798.8 mm)
[MakerNotes:Camera] LensModel                   : EF100-400mm f/4.5-5.6L IS II USM +2x III
[MakerNotes:Image] ImageUniqueID                : 92b2d8412c464a4ba1b91d62c962c613
======== /home/jrm/photos/2024Jun17/IMG_0265.dr4
[ExifTool]      ExifToolVersion                 : 12.63
[CanonVRD:Image] LensFocalLength                : 800
======== /home/jrm/photos/2024Jun17/IMG_0265.JPG
[ExifTool]      ExifToolVersion                 : 12.63
[EXIF:Camera]   FocalLength                     : 800.0 mm
[MakerNotes:Camera] MaxFocalLength              : 800 mm
[MakerNotes:Camera] MinFocalLength              : 200 mm
[Composite:Camera] FocalLength35efl             : 800.0 mm (35 mm equivalent: 798.8 mm)
[EXIF:Image]    LensModel                       : EF100-400mm f/4.5-5.6L IS II USM +2x III
[MakerNotes:Image] ImageUniqueID                : 91b2d8412c464a4ba1b91d62c962c613

exiftool -s -G0:2 -ExiftoolVersion -"*focallength*" -lensmodel -ImageUniqueID /Volumes/jrm/photos/2024Jun17/IMG_0265.CR3                    [ExifTool]      ExifToolVersion                 : 12.90                                                                               
[MakerNotes:Camera] FocalLength                 : 800 mm
[MakerNotes:Camera] MinFocalLength              : 200 mm
[MakerNotes:Camera] MaxFocalLength              : 800 mm
[Composite:Camera] FocalLength35efl             : 800.0 mm (35 mm equivalent: 798.8 mm)
[MakerNotes:Camera] LensModel                   : EF100-400mm f/4.5-5.6L IS II USM +2x III
[MakerNotes:Image] ImageUniqueID                : 92b2d8412c464a4ba1b91d62c962c613
Johns-iMac.local[20742]$ exiftool -s -G0:2 -ExiftoolVersion -"*focallength*" -lensmodel -ImageUniqueID /Volumes/jrm/photos/2024Jun17/IMG_0265c.JPG
[ExifTool]      ExifToolVersion                 : 12.90
[MakerNotes:Camera] FocalLength                 : 400 mm
[MakerNotes:Camera] MinFocalLength              : 100 mm
[MakerNotes:Camera] MaxFocalLength              : 400 mm
[Composite:Camera] FocalLength35efl             : 400.0 mm
[EXIF:Image]    LensModel                       : EF100-400mm f/4.5-5.6L IS II USM +2x III
[MakerNotes:Image] ImageUniqueID                : 0db2f09024464a4ba1b91d62c962c613
Johns-iMac.local[20743]$ exiftool -s -G0:2 -ExiftoolVersion -"*focallength*" -lensmodel -ImageUniqueID /Volumes/jrm/photos/2024Jun17/IMG_0265.JPG
[ExifTool]      ExifToolVersion                 : 12.90
[MakerNotes:Camera] FocalLength                 : 800 mm
[MakerNotes:Camera] MinFocalLength              : 200 mm
[MakerNotes:Camera] MaxFocalLength              : 800 mm
[Composite:Camera] FocalLength35efl             : 800.0 mm (35 mm equivalent: 798.8 mm)
[EXIF:Image]    LensModel                       : EF100-400mm f/4.5-5.6L IS II USM +2x III
[MakerNotes:Image] ImageUniqueID                : 91b2d8412c464a4ba1b91d62c962c613


[Phil Harvey]

I'm confused.  What is the difference between the first set of files and the second?

You should add the -a option to see the duplicate tags.  Otherwise you will only see one FocalLength tag.

- Phil

[JohnMoyer]

I'm confused.  What is the difference between the first set of files and the second?

You should add the -a option to see the duplicate tags.  Otherwise you will only see one FocalLength tag.

- Phil

Thanks for exiftool

Maxfocallength and Minfocallength included the focallength of the extender before and do not include it now.
Same image, one has focallenght 200-800 and other 100-400. I do not know which version of exiftool is correct because I had copied tags from CR3 file to JPG. The 2 versions of exiftool handle focallength differently. I do not know whether the difference between exiftool versions is intentional.

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======== /home/jrm/photos/2024Jun17/IMG_0265c.JPG
[ExifTool]      ExifToolVersion                 : 12.63
[EXIF:Camera]   FocalLength                     : 800.0 mm
[MakerNotes:Camera] MaxFocalLength              : 400 mm

...

[ExifTool]      ExifToolVersion                 : 12.90
[MakerNotes:Camera] FocalLength                 : 800 mm
[MakerNotes:Camera] MinFocalLength              : 200 mm
[MakerNotes:Camera] MaxFocalLength              : 800 mm



[Phil Harvey]

Hi John,

Perhaps you could sort this out.  The change in ExifTool was due to tag decodings that you suggested in this thread.

- Phil

[JohnMoyer]

Hi John,

Perhaps you could sort this out.  The change in ExifTool was due to tag decodings that you suggested in this thread.

- Phil

I will try to figure it out. Most likely, it was my mistake in copying tags from CR3 to JPG files.

Thanks again.

John