Upvote:2
It would take a better scan to be 100% certain, but it looks like an Adrian helmet, with crossed cannons indicating an artillery unit.
Branch insignia in the form of a grenade for line infantry and cavalry, a bugle horn for chasseurs, crossed cannon for artillery, an anchor for colonial troops and a crescent for North African units was attached to the front.
A nice example can be seen at the Australian War Memorial:
So yes, French, WW1 era, after 1915.