Reading exif from tiff files returns nothing

[Lastwerk]

Hi there,
I'm trying to read exif and iptc data from tif and jpeg using vb.net with Magick.NET-Q8-x86 v12.1.0.

i can always read the iptc profiles:

        Dim img As MagickImage = New MagickImage(filename)
        Dim prof = img.GetIptcProfile()

Using GetExifProfile() returns Nothing when reading from tif, but works fine on jpeg files.

I also tried reading exif data via GetAttributes(), but I only get the tiff: tags.

       For Each attr In img.AttributeNames
            Debug.Print(attr)
        Next

A sample image can be found here: http://lastwerk.de/exif/exifdemo.tif

With exiftool, Gimp, Windows Explorer I can see the data.

Are there alternative functions to get exif data from tif files I could use?

Thanks for any ideas...