Ron,
Okay this is somewhat complicated so please bare with me.
There is a standard Exif tag for lens model (0xa434) that typically has manufacturer's full description of lens, written by the camera. If this is present we use this to report lens used. Unfortunately by using FTZ adapter with whatever lens you had (8-15mm), the Z6 isn't able to read or create the normal full model name for the lens that was used. So the Z6 writes this tag (0xa434) but the value is empty (might as well not write the tag at all but an empty value means something different than the absence of the tag itself
).
If this standard lens model tag is missing, then PM tries to use various Exif Maker Note fields to construct what the lens used would be (not as good as the official lens model from camera). When saving a RAW file to JPG, PM (and other software) removes the Exif Maker Note. Henceforth when viewing the saved JPEG, PM (or any other software I suspect) has no idea what lens was used (no 0xa434 tag and no maker note to "create" lens used).
It turns out that there is a "bug" in that PM isn't preserving any Exif lens model when saving JPEG (IOW if you used a standard Z mount lens without FTZ adapter). We will put this on list to fix. But with that special lens and FTZ adapter, there isn't much that can be done other than perhaps put the lens used variable in some unused IPTC field like special instructions (some folks put all sorts of Exif info in that field because it sticks regardless of the existence of any Exif data whatsoever).
HTH...
--dennis
