The two principal field pieces of the German artillery corps are very clearly rendered in black and white on the attached PDF: the 105mm field gun and the 150mm howitzer. Also illustrated are two German trench mortars; 240mm and 305mm, respectively.
WW1 German Trench Mortar IllustrationWW1 German field gun imageWW1 German Trench Mortar DrawingWW1 German Field Artillery infoGerman Artillery Corps field piecesWW1 German 105mm field gunWW1 German 150mm howitzer 1914-1918WW1 German Trench Mortar Information