Scot ancestors, either Canadian military or Scot?

[frank_a]

I have been sorting through family history stuff this month as prep for putting together a genealogy for my 3 sons (and one grandson so far!). In sorting through "stuff" from the Campbell side of the family, I came across these 5 pics of kilted folk. Any idea what branch of who's military these folks were with? I don't have names of the fellows, just know that somehow they're ancestors of mine.

Thanks for any help!

Frank