Adding Manual lenses with no EXIF data to Categories.

[Bartman66]

I have several manual lenses that do not have electrical contacts and therefore do not write any info the image when taking a phot. Id like to know howto AXIF data to the image so that the lens shows up in the lens category in Category view pannel.  I've done a search but can't find anything on this. I'm specifically looking to what Exif data I need to modify and how I do it.  i.e one of my lenses is a Tokina RMC 17mm F3.5 Canon FD. How do I load this into the image metadata so that I have it automatically listed in the lens category?

Many Thanks

[Mario]

There are usually several EXIF tags (between 2 and 7) involved in figuring out a lens. The lens model etc. is not written as plain text into the EXIF but as vendor-specific numbers. ExifTool uses these numerical tags to lookup lens models in internal tables. IMatch uses one of the following lens tags to produce the lens tag it uses internally:

Composite\Nikon-LensID\LensID
Composite\Ricoh-LensID\LensID
Composite\XMP-LensID\LensID
Composite\Exif-LensID\LensID
XMP::exifEX\LensModel\LensModel
Exif::Main\42036\LensModel
Exif::Main\42034\LensInfo
Composite\Nikon-LensSpec\LensSpec
Composite\Canon-Lens\Lens

depending on which tag is filled. The Composite tags are virtual tags ExifTools makes up on-the-fly from various other lens tags.
Check out the lens-related tags for some of your images to get a feel for this. You cannot modify the Composite lens tags or the special IMatch lens tag.

[Bartman66]

Thanks Mario. So my next question are a)how do I find out if my lenses are in the internal table b) what info do I need to insert into my images to enable looking up my lenses c) if my lenses are not in the internal tables how to I get them added .

Cheers.

[Mario]

I have no idea, sorry.

This is all ExifTool magic and ExifTool produces the lens info from the EXIF record written by your camera.
I'm not sure if you can tag an image with a lens later. This would be a question for the ExifTool forum: https://exiftool.org/forum/

If you really need this, I would suggest putting the lens name into a free-text tag or an Attribute for these images. And then use that for creating a data-driven category.
You could even use the Metadata Mechanic or a Metadata Template to copy the lens info for your other files into the same tag. Or the Attribute importer to import the EXIF lens info into the same Attribute you fill the lens info into manually for non-EXIF images. Not sure if this is really worth the effort, though.

[Bartman66]

Thanks Mario. I'll investigate on the suggested forums. Seems like a lot of work.
A easy way todo this would  be a cool feature for incorporating into imatch. 

I'll look at using a free test attributed for the moment .

Cheers.

[Mario]

If camera vendors just would store the lens name as a text in an XMP field, everything would be so much easier.
Or abandon the 30 year old EXIF crap and switch to XMP.
But they don't and that's that.

I doubt there are many users with manual lenses around. And if, they usually don't care to somehow fiddle made up lens info into an EXIF record.
IMatch offers you so many ways to achieve this, without dealing with EXIF. Just use an Attribute or free-text field and then combine all your manual lenses in a dedicated data-driven category. Easy. Fast. Problem solved.