No luck.
I did the following:
exiv2 -pt NIKON\ D4_03-Jun-21_5189_8994.nef |grep -i ‘lens|model|make|focal’
which o/ps"
Exif.MakerNote.Offset Long 1 13448
Exif.MakerNote.ByteOrder Ascii 3 MM
Exif.Nikon3.LensType Byte 1 (0)
Exif.Nikon3.Lens Rational 4 70-210mm F4
Exif.Nikon3.LensFStops Undefined 4 6
Exif.NikonLd3.FocalLength Byte 1 146.7 mm
Exif.NikonLd3.LensIDNumber Byte 1 Nikon Nikkor 500mm f/4 P ED IF + TC1.6AF
Exif.NikonLd3.LensFStops Byte 1 F6.0
Exif.NikonLd3.MinFocalLength Byte 1 71.3 mm
Exif.NikonLd3.MaxFocalLength Byte 1 207.5 mm
Exif.NikonLd3.MaxApertureAtMinFocal Byte 1 F4.0
Exif.NikonLd3.MaxApertureAtMaxFocal Byte 1 F4.0
Exif.NikonFl3.FlashFocalLength Byte 1 n/a
Exif.Photo.FocalLengthIn35mmFilm Short 1 145.0 mm
And:
exiv2 -pv NIKON\ D4_03-Jun-21_5189_8994.nef |grep -i ‘lens|model|make|focal’
with o/p:
0x0001 MakerNote Offset Long 1 13448
0x0002 MakerNote ByteOrder Ascii 3 MM
0x0083 Nikon3 LensType Byte 1 0
0x0084 Nikon3 Lens Rational 4 700/10 2100/10 40/10 40/10
0x008b Nikon3 LensFStops Undefined 4 72 1 12 0
0x000b NikonLd3 FocalLength Byte 1 117
0x000c NikonLd3 LensIDNumber Byte 1 3
0x000d NikonLd3 LensFStops Byte 1 72
0x000e NikonLd3 MinFocalLength Byte 1 92
0x000f NikonLd3 MaxFocalLength Byte 1 129
0x0010 NikonLd3 MaxApertureAtMinFocal Byte 1 48
0x0011 NikonLd3 MaxApertureAtMaxFocal Byte 1 48
0x000c NikonFl3 FlashFocalLength Byte 1 0
0xa405 Photo FocalLengthIn35mmFilm Short 1 145
And changed my .exiv2 conf file to:
[nikon]
3=Nikon Nikkor 500mm f/4 P ED IF + TC1.6AF
92=800mm
129=800mm
145=800mm
Only the byte value/ tag value of 3 is “seen” by exiv2 program. All the rest are ignored. Even just editing and leaving the
3=Nikon Nikkor 500mm f/4 P ED IF
which refers to the original lens without the TC the exiv2 program does not overwrite the rest of the exif properties.
I did not go further digging into tags to see if some other tag value is recognised by this process.
All changes were viewed directly on the Geeqe image viewer that seems to use exiv2 to refer to exif data. To be sure I did run occasionally the exiv2 tool directly.
Finally I did put the first line after the [nikon] declaration as the last line in the .exiv2 config file which made no difference (the only line declaration that is recognised).
Thank you for the info about the distortion on the link. It is clear to me now how to take sample photos. That will complete the process of lensfut.xml as soon as I go out and take some more pictures for the 500mm lens.
For the TCed 500mm I have to rest my case.