manual focus - What is the correct, standard EXIF metadata to add for Rokinon 8mm fisheye lenses?

I own a Rokinon 8mm Ultra Wide Angle f/3.5 Fisheye Lens for Canon EF Mount. This is a manual lens not electrically connect to the Canon 60D body I use it with.

With exiftool I want to add the correct EXIF lens metadata to the resulting pictures.(*) From this SE questions I gather that this is not straight forward, so I have the question: For this lens what are the correct texts for the tags LensInfo and LensModel? Does maybe a website or database exist which lists standard strings for different manual lenses?(**)

And are there other EXIF text tags I should set in the photos as well? (I am thinking here of tags programs like Hugin might use to determine that the lens is a fisheye lens).

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(*) It would be a bonus if Aperture and in future LightRoom pick the lens up by these tags.

(**) For some electronic lenses these standard strings obviously exist: E.g. in the Canon Maker tag LensType the value 488 stands for "Canon EF-S 15-85mm f/3.5-5.6 IS USM".

Answer

If you want Hugin to auto-recognize and correct for the lens, then probably the right tag to use is Samyang 8mm f/3.5 Fish-Eye CS, because this is the entry in the lensfun database, which is now integrated into Hugin use. In the slr-samyang.xml file the entry is:

    
        Samyang
        Samyang 8mm f/3.5 Fish-Eye CS
        Samyang 8mm f/3.5 Fischauge CS
        Pentax KAF
        Canon EF
        Nikon F AI
        Fujifilm X
        Sony Alpha

        Sony E
        4/3 System
        Micro 4/3 System
        Samsung NX
        1.534
        stereographic
        
            
                                                 bb="-0.0002711" cb="0.0008531" vb="0.9998496" />

            
            
        
    

The lens is manufactured by Samyang in Korea, but is generic-branded with many many names: Rokinon, Vivitar, Falcon, Walimex, Bower, Opteka, Bell and Howell, Polar, Phoenix, and Pro-Optic are among the many names of Samyang. Weirdly, Vivitar calls it a 7mm, and Pro-Optic a 6.5mm, but they're all the same lens with the same stereographic mapping.

Also, there's an easier way than going to the command line to tag up lenses. I own a Rokinon 7.5mm f/3.5 fisheye for the micro four-thirds mount, as well as adapting several manual lenses for my Canons. I tag up the EXIF for all my manual lens and scanned film images in Lightroom with the LensTagger plugin. LensTagger is a GUI frontend for exiftool, which makes the job much easier than typing the command by hand on the command line every time. It can save "presets" of specific lenses you use often, and writes the following fields:

• Lens


• LensModel



• FocalLength


• MaxApertureValue


• FNumber


• FocalLengthIn35mmFormat

The Lens and LensModel fields can take any string, and will, indeed show up in Lightroom intelligibly. You don't need to worry about numeric coding in this case. When in Lightroom, you can set up the lens profile default for whatever tag you come up with. I tag my Rokinon 7.5 shots with "Rokinon 7.5mm f/3.5 UMC fisheye", and then set it to default to Stereographic remapping with kenw's Samyang 7.5 f/3.5 lens profile for lens correction. I'm sure there's a profile out there for the dSLR 8mm version.