Thats where I was looking but ran into where it appears that if there is no actual exif date in the file, the field would reflect the file date.
What I was hoping was to find images where this is missing as that would imply they're not from a camera/scanner/whatever, at least in that particular form.
This way directories where there's all kinds of images dumped in.. media from others, archives, grabs from web pages, screen shots, etc. where there are non-camera / scanner sourced images.. That these can be eliminated in a particular library, by not ingesting them in the first place.
As best I can come up with is arranging them by {model} since that would pretty much eliminate something that isn't native from a device that writes metadata in the file. Of course, if there are images grabbed from web pages or such that have complete metadata, those would be imported. Thats fine.
I'm trying to keep a particular library with nothing but images where the date shot is actually embedded. This way when arranging by date/timestamp, the outcome is going to be pretty close to 100%.
All these applications/utilities that do image sorting seem to resort to the filesystem date/timestamps if there is no exif data, Photo Mechanic included.