Military intelligence photography is used to select bombing targets, determine bombing accuracy, assess bombing damage, determine enemy orders-of-battle, analyse equipment capability, pinpoint defence positions, serve as a basis for maps and to search for indications of enemy initiatives or intentions.

Aerial reconnaissance photography has been employed by British forces since the First World War (1914-1918), but little development of cameras or collection methods was made in the years leading up to the Second World War (1939-1945). In the late 1930s, however, an Australian civilian, F Sidney Cotton, used a private Lockheed 12 aircraft with concealed cameras to take clandestine photographs of Germany. Following on from this work, Cotton was instrumental in persuading the RAF to mount cameras in high-performance aircraft, such as the Supermarine Spitfire.

The two main photographic reconnaissance (PR) aircraft used during the Second World War were the Spitfire and the De Havilland Mosquito. With all armament removed and replaced by cameras and additional fuel tanks to extend their range, they relied on speed and altitude for survival. These types of aircraft could range up to 2,000 miles, taking photographs from altitudes up to 44,000 feet though missions usually took place around 22,000 feet with some at very low level. The reconnaissance units used several airfields in Scotland as forward bases for photographic sorties over enemy occupied Scandinavia. The RAF PRU made flights over Scotland to train both pilots and interpreters in the skills required for this work. Spitfires of A Flight, No. 1 PRU, used Wick airfield in Caithness as a base for operations over Norway and northern Germany from 1940 to 1942. It was a PRU Spitfire from Wick that photographed the German battleship Bismarck arriving in Grimstadtfjord, south of Bergen, Norway, on 21 May 1941.

Formed from the merger of H and L Flights of the PRU, No. 540 squadron was equipped with the longer-ranged De Havilland Mosquito and operated from Leuchars, Fife, from 19 October 1942. It was a Mosquito of 540 squadron which discovered the V-2 missile launch site at Peenemunde, on the Baltic coast, and thereafter the unit was involved in the regular acquisition of images from the site. No. 8 OTU was formed in May 1942 and was based initially at Fraserburgh, then later at Dyce. Created specifically for photo-reconnaissance training, its pilots often made long flights of up to six hours, usually making an entire circuit of Scotland and northern England. After transfer to Dyce in March 1943, the unit's 37 Spitfires and 25 Mosquitoes ranged all over the UK on high-level photo-reconnaissance training flights and a small number of operational sorties were made over Norway in 1944.

The prints in this collection represent a small selection of the total created during the wartime operations of photo reconnaissance pilots in Scotland. The negatives of these prints were deliberately destroyed during the 1950's after their chemistry had become unsafe due to their nitrate base. Many of the prints still retain their 'chinagraph' pencil marking where trainee photo-interpreters have annotated 'features of note'.

The coverage obtained during any PR sortie is limited by the size and number of cameras an aircraft can carry. The Spitfire and Mosquito were both versatile collection aircraft and could carry cameras in a variety of configurations, according to mission requirements. The Mosquito often carried five cameras: one mounted obliquely in the fuselage plus two pairs of split-verticals of different focal lengths to give stereoscopic coverage of a target and its surrounding area, though for low level missions one camera could be mounted facing obliquely forward in the nose, with two others in dummy drop-tanks under the wings, synchronised to give stereo-pairs. Split verticals allowed for greater coverage of the ground on one overflight. Cameras were remotely operated by the pilot and were kept free from frost and condensation by having warm air directed over them from the engines. The most common British cameras used were the F8, F24 and F52. The F8 high altitude daytime survey camera could be fitted with 20-inch (508mm), 36-inch (914mm) and 40-inch (1016mm) lenses. The F24 Universal standard aircraft camera for day and night photography, could be fitted with 3.25-inch (82mm), 5-inch (127mm), 8-inch (204mm), 14-inch (356mm), and 20-inch (508mm) lenses, weighed 40 pounds (18kg) and produced 125 exposures of 5 x 5 inches (12.5mm x 12.5mm). It could be carried by photo-reconnaissance Spitfires in a variety of configurations, such as one mounted obliquely in a pod under each wing, or two mounted vertically and one obliquely in the fuselage behind the pilot. The F52 high altitude day reconnaissance camera was introduced after January 1942 and could be fitted with 5-inch (127mm), 8-inch (204mm), 14-inch (356mm), and 20-inch (508mm) 36-inch (914mm) or 40-inch (1016mm) lenses, producing 500 exposures of 8.5 x 7 inches (23mm x 18mm). Weighing 78 pounds (35kg), its long focal length was particularly suitable for high-altitude reconnaissance and it became the standard British camera for most of the war.