Black and white comparison here

The following is some further information:

This picture was taken near Cape Helles, during the infamous Gallipoli campaign that has become one of the defining slaughters of the First World War. Through the smoke we can see the cannon's target is a distant hill; there were four significant hills that were heavily defended by the Ottomans during the Cape Helles landings, and I suspect that the image shows the field cannon firing from Hill 138 to 114, 141 to 138, or from 236 to 141 (hills named after their altitudes). Cape Helles is located on the southern slope of Hill 141, so perhaps that is the most probable location.

The field gun shown here was a Mk I BL 60-pounder, marked on one of the two upper tubes with the nickname 'Annie'. The gun is shown here at full recoil, with one in its resting state shown in the background. Neither of the two prominent tubes on top of the gun were its barrel, which is seen partially hidden below them. These big tubes were the weapon's recoil system, and housed hydraulic buffers. BL stands for Breech Loading, as opposed to ML, or Muzzle Loading. In this case the 'breech' was the sealed hatch that can be seen at the rear of the gun. The weapon's calibre was 5 inches, and the Mk I fired The Mk I fired 2 CRH shells for the majority of the war. The 60-pounder was used for the entirety of the first world war, with minor improvements made to its construction. It continued to exist in various iterations until its withdrawal in 1941.