The F-7 was a photographic reconnaissance variant of the B-24 Liberator, the first prototype the XF-7 was modified of a B-24D,  all bombing equipment was removed and had eleven cameras installed, they being mounted in the nose, bomb bay and the aft fuselage.  The standard recce variant was the F-7A, this was based on the B-24J airframe. It had a three nose and three bomb bay cameras fitted, 182 conversions to this type were made.
The F-7B differed from the F-7A in carrying all six cameras only in the aft bomb bay, with the nose camera installation being deleted. Most F-7Bs were converted from B-24Ms. However, a few B-24Js & Ls became F-7Bs.

The F-10 was the designation given to 45 B-25Ds Mitchell's that were modified for photographic reconnaissance work. All armament, armour and bombing equipment was removed. Three K.17 cameras were installed, one mounted vertically, with the other two mounted at oblique angles within blisters on each side of the nose. Also a vertical cameras could also be installed in the aft fuselage. Although designed for combat reconnaissance, these aircraft were mainly used for ground mapping.

The F-9 Flying Fortress, this was the photo-recce variant of the B-17 bomber. The first type to be converted was the B-17F. These conversions had the weapons bay modified to hold cameras and other surveillance equipment. Later a camera was mounted in the nose and some of the defensive armament was retained. This became the F-9A and the F-9B (which had a different camera installed) of which there were a final 25 conversions completed.

Based on the P-38 Lightning, the first photographic  reconnaissance variant, the F-4-1 was based on the P-38E. With all the weapons removed from the noise bay, this left a spacious area to install cameras. Nine of these aircraft were deployed to the United Kingdom as part of the 5th PS (Photographic Squadron) in mid 1942. Later, a number of the reconnaissance versions of the P-38G, designated the F-5A, started to arrive in the UK and became part of 13th Photographic Squadron. Listed as the principal USAAF photographic reconnaissance aircraft, it was continually upgraded, F-5Bs, F-5Cs and F-5Es were in regular use, with all three variants often operating together in the same squadron.
The Lightning could be fitted with a number of combinations of cameras, examples being;
Three K.17s with 6" lens mount so they covered horizon-to-horizon and another combination being a 'split' pair of K.17s fitted with 24" lens plus a vertical K.17 fitted with either a 12" or 24" lens.
In late 1944 the F-5 was starting to be outclassed by the latest German fighters, in the last 6 months of the war, the F-5 would usually escorted by up to twelve P-51 fighters.

Click for an enlargement

Due the aircrafts early evaluation in the UK, it was noted for its poor high altitude performance. So the early Mustang Mk.1s began the service life with the RAF in the tactical reconnaissance role. They equipped 14 RAF Army Co-operation Command squadrons. Behind the cockpit was a large, transparent rear quarter-light which, because of the shape and position of the pilot's seat, this was almost useless for rear vision. However; it was perfect for the installation of a single F.24  or K.24 port facing oblique camera. Low-level photo-recce was not glamorous duty, but the early Mustangs was well suited to it.  To ensure that the pilot took the the right photographs, the target was lined-up with a mark on the port wing, thus allowing images to be taken from a distance, reducing the risk the the aircraft being hit by anti-aircraft fire. The Mk.lA differed by having four cannons fitted, unlike the Mk.l which had only four machine guns. Later versions of the Mustang, called the P-51, were also used in the tactical photo-reconnaissance role. Designated the F-6 a number of variants were produced - 
37 F-6A, 35 F-6B, 91 F-6C, 146 F-6D & 163 F-6K.

The P-39 was one of America's first-line pursuit aircraft first flying in December 1941. Twenty seven  were converted into P-39F-2 sub-variants which were equipped for the ground-attack and reconnaissance role.

 
Spitfire PR XI

The Supermarine Spitfire PR XI, an unarmed photo-recce variant of F Mk IX (fighter), was used during the later part of 1943 by the US 8th Air Force which received twelve PR XI's, they equipped the 14th Photographic Squadron, 7th Photographic Group and were based in at Mount Farm Airfield in Oxfordshire, UK. All the Spitfires delivered were in the standard RAF "PRU Blue" with the aircrafts serial number painted on the tail.

A 120 Mosquitoes were ordered for photographic reconnaissance duties, however, only 40 were delivered and were given the designation F-8-DH. Unlike the RAF PR.XVI Mosquito which had its cameras mounted in the bomb-bay, the F-8-DH had its mount in the nose. Only sixteen reached Europe, where eleven were passed to the RAF in exchange for the PR.XVI variant and five were sent to Italy. The RAF provided 145 PR Mk XVI aircraft to the 8th USAAF Air Force between 22 April 1944 and the end of the war. These were used for a variety of photographic and night reconnaissance missions by various USAAF units.

(c) USAF - Click for an enlargement