Just ran across this close-up of some bavarians. The second from bottom wears a bing type helmet with pattern M91 reserve chinstrap - I did not see that yet. The visor of the field cap on the bottom looks so small, is that standard? No date.
Robert, I can see stitching holding the front visor on, and the leather of the liner curving up over the edge above the ear, so that is a leather Pickelhaube.
The Schirmmütze is the type commonly found prior to around 1900 or so with the teeny brim.