Nick,
I can now add some details. It is a group photograph of the regimental staff of Kurmärkisches Feldartillerie-Regiment Nr. 39 probably in the late summer of 1916 either in Northern France or in Rumania. Baron von Weitershausen had assumed command of the regiment on 16 July 1916 and the regiment left France for Rumania at the beginning of September 1916. He is flanked by the regimental adjutant, Leutnant Karl Beckurts and the regimental veterinary officer, Stabsveterinär d.R. Hesse. Leutnant d.R. Burkhardt Helferich, the Regiments-Ordonnanzoffizier (assistant adjutant) is number 4 and Musikmeister Schultze is number 5. Vizewachtmeister Hagemann is number 6.
Regards
Glenn