Tuesday, September 20, 2016

British Photographic Reconnaissance Cameras in WW1 - Part 6

STEREO PHOTOGRAPHY

The ability to see in three dimensions or stereo is common to all mammals with their eyes positioned to look forward. Each eye perceives an object from a slightly different position which is translated by the brain to 3-D image. A quick way to appreciate this is to hold up a finger and look at it with one eye then the other; you will find it moves against its background this is parallax.

Stereoscopic Imaging is a technique that uses parallax to create or enhance the illusion that an image has depth by showing two slightly offset images separately to each eye of the viewer. Both images are of the same scene or object but from a slightly different angle or perspective. This is meant to trick your brain into synthesizing that the small lateral displacements between the positions of the images are implying spatial depth. It provides a more familiar view and a relative level of detail between objects on the ground greatly aiding the interpretation of known and unknown objects. Special equipment is usually required in order for the brain to make sense of the picture. During WW1 various stereoscopic viewers were used.

THE BRITISH ARMY ON THE ITALIAN FRONT, 1917-1918 
British Intelligence Officer uses a stereoscopic viewer to interpret aerial reconnaissance photographs © IWM (Q 26946)

The RFC’s first stereo pictures were collected using the A Type hand held camera and necessitated a rapid plate changing process. Experiments were carried out using what was virtually two Type A bodies joined together with the lenses spaced apart the required distance to obtain stereo images. This exposed two plates at the same time producing the necessary parallax.

AERIAL PHOTOGRAPHY, FIRST WORLD WAR 
Pair of aerial cameras on the Mackenzie stereo fitting mounted on a scarff ring. © IWM (MH 33749)

MINISTRY OF INFORMATION FIRST WORLD WAR OFFICIAL COLLECTION 
Stereo Mount for P1 Type Cameras. © IWM (Q 12287)

Stereo photography significantly enhanced the interpretation of aerial photographs. The 3-D effect was particularly useful at revealing camouflage attempts which to the naked eye, on a single mono photograph, would remain hidden. The photograph below is a stereo pair taken over Mount Kemmel, South West of Ypres on 22 July 1918.

GAUNTLETT HENRY 
Stereoscopic aerial photograph showing area south of Mount Kemmel taken by No 10 Squadron Royal Air Force 22 July 1918. © IWM (Q 115374)

Tuesday, July 12, 2016

British Photographic Reconnaissance Cameras in WW1 - Part 5

TYPE P1, 18, and F1

The Type P1 designed during the war as a replacement for the A Type specifically for oblique photography used 5 x 4 inch plates in a Machenzie-Wishart holder. The shutter was a hand wound focal plane type, the lens mounted in a fixed cone. Two hand grips were fitted, together with a tube and cross wire view finder which was below the body to enable the operator to stay low in the cockpit whilst using. A special sling was sometimes used in conjunction with the gun scarfe ring in open cockpit aircraft. Two cameras could be slung side by side in this mount to obtain stereo photographs.

MINISTRY OF INFORMATION FIRST WORLD WAR OFFICIAL COLLECTION 
Type P1 Camera – Replacement for A Type specifically for oblique photography – stereo mount shown. © IWM (Q 12287)

The Type 18 was also used primarily for oblique work, designed and built by the Houghton-Butcher Company. Using single, double sided plate holders the camera took 5 x 4 inch glass plates. It had viewfinders on top and the bottom of a rigid camera body. Slit width and shutter tension were adjustable together with lens diaphragm for exposure control

Camera Type 18 
Camera Type 18 © IWM (PHO 23)

The Aero Camera or F Type was the first and only official film camera used from the air in the war, and appeared in 1916. It was rejected in France but was used extensively in the Middle East, where large tracts of country were mapped by means of this camera. The F Type camera was designed to take a continuous series of pictures on a roll of film 5 inches wide and either 25 of 50 feet in length, a 50 feet roll giving a series of 120 exposures. The camera with an 8 inch lens was usually fitted on a bomb rack on the underside of the aircraft. Air movement through the camera’s small propeller provided the power necessary to operate the camera which was controlled remotely by the pilot.

BRITISH AERIAL CAMERAS OF THE FIRST WORLD WAR. 
Type F1 Film Camera. © IWM (HU 86135)


Friday, July 1, 2016

British Photographic Reconnaissance Cameras in WW1 - Part 4

TYPE LB and BM

The LB Type was the next and last in this series. The LB Type was a further improvement on the L Type and made its appearance in 1918. In general design it was similar to the L Type however the camera mechanisms had been significantly simplified greatly assisting repair and maintenance. The key alteration was the inclusion of an easily removed self-capping focal plane shutter, which could be readily replaced without disturbing the other parts of the camera mechanism. Different lens mounts allowed the use of lenses of 4”, 6”, 8”, 10”, and 20” focus to be used. The lens mounts were interchangeable and were attached via a bayonet fitting on the lower part of the camera body. Other improvements included an exterior lever for adjusting the shutter slit, and a simple method to convert the changer mechanism from hand to power operation. This camera was still in use well into the 1920s having been re-designated P7.

FIRST WORLD WAR 1914 - 1918: AERIAL RECONNAISSANCE 
Type LB Camera being handed to an Observer in a DH4 © IWM (IWM FLM 3582)

MINISTRY OF INFORMATION FIRST WORLD WAR OFFICIAL COLLECTION 
Type LB Camera being inspected © IWM (Q 12287)

It was during 1918 that the RAF formally changed their naming convention for aerial cameras. P was used for plate cameras, F for film cameras, and G for gun cameras.

The BM Type introduced in 1918 was the ultimate development of the B Type and included all the refinements of the LB Type. Its development was triggered by the need for higher resolution pictures from aircraft that were now flying higher. This was the largest camera used by the RAF and was made entirely of metal. The focal lengths of the lenses ranged from 7” to 20”. The BM Type was an extremely heavy camera and it was not easy to change the magazines which when loaded with plates were also heavy and awkward to handle. When ready for flight with a 20” lens cone and 3 magazines the camera weighed 82lbs.

BRITISH AERIAL CAMERAS OF THE FIRST WORLD WAR. 
BM Type Camera © IWM (HU 86136)

Friday, June 10, 2016

British Photographic Reconnaissance Cameras in WW1 - Part 3

TYPE E and L

The bulkiness of the C Type camera, coupled with photograph distortion issues caused by expansion and contraction of the wooden camera body due to changing atmospheric conditions, led to the development of the metal bodied E Type camera. This camera began to be introduced in the autumn of 1916. Metal construction replaced the earlier wood and tubular lens extensions were available to enable varying focal lengths of between 8 to 101/2 inches to be pre-selected. Full automation of the plate transfer and shutter operations was also achieved. This camera, ready for flight, weighed approximately 31 lbs.


E Type Aerial Camera © IWM

The BEF’s experience on the Somme in 1916 highlighted the need for large quantities of aerial photographs. To meet this demand the RFC started to introduce the first near fully automated camera, the L Type, in early 1917. This camera built by the Williamson Engineering Company was the RFC’s first quantity production camera. The lessons gleaned from the use of the earlier cameras were incorporated and new manufacturing methods, alloy castings, were employed.

AERIAL PHOTOGRAPHY, FIRST WORLD WAR 
L Type Aerial Camera © IWM (MH 33751)

Illustrated above is a Williamson L Type vertical aerial camera installation as fitted for external use on an aircraft. Connected to the camera body is a propeller and flexible drive shaft for automatic operation, and a remote shutter-release attached by a Bowden cable. The camera body was a light aluminium casting, containing the plate changer, gear driving mechanism and the focal plane shutter. To this, a cylindrical metal lens adapter was fitted which, on initial models, contained a lens of 6” focal length (seen above): subsequently lenses from 8” to 10½” became standard. The shutter was the same “Goertz-Anschutz” roller-blind type as that on earlier models, fitted with a sliding saddle to adjust the width of the opening, and an internal lens-cap which was mechanically removed during exposure by the shutter release. The magazines were of the same build and capacity as those on the C and E Types, and were placed in similar ‘donor’ and ‘receiver’ positions on the plate-changing apparatus. The L Type could be mounted in any vertical position, either inside or outside the fuselage, and could be operated manually or automatically. For manual operation the first models were fitted with a plunger release, but because of the camera-movement caused by its operation at the moment of exposure, this was often disabled or removed and a Bowden cable used in preference, as seen on this example. When in automatic use, the power came from a small propeller turned by the air stream and connected to the camera by a flexible drive shaft. The operator depressed the release lever to actually take the photograph, the exposed plate was then changed and the shutter was reset by a pinion drive activated by the propeller every four seconds. The ‘L’ Type weighed 37 lbs.

AERIAL PHOTOGRAPHY, FIRST WORLD WAR 
L Type Aerial Camera on BE2c © IWM (MH 33736)


Monday, May 23, 2016

British Photographic Reconnaissance Cameras in WW1 - Part 2

TYPE B and C


The problems of manual plate changing were largely overcome in August 1915 when a semi-automated exposed plate transfer and shutter operation mechanism was attached to an A Type camera body. The resulting camera was designated the C Type. The plate transfer mechanism was fitted with three 18 plate magazines, two containing the unexposed plates, the other empty ready to receive the first 18 plates once exposed. A series of magazine switching mechanisms allowed the exposure of all 36 plates without the need to remove any of the magazines from the camera. This camera fitted with a 10 inch lens, three magazines, two containing 18 plates each, weighed about 26 lbs. The C Type camera, fitted on a wooden frame and mounted on the side of the aircraft became the standard RFC issued camera until the spring of 1917.

16 WING PHOTOGRAPHIC SECTION (RFC/RAF) IN SALONIKA 1917-1919 
16 Wing Photographic Section (RFC/RAF) in Salonika 1917-1919 - Type C camera carried by fitter © IWM (HU 97468)

PHOTOGRAPHY DURING THE FIRST WORLD WAR 
Type C camera fitted to a BE2c © IWM (Q 33850)

The Type B was developed and introduced in mid 1916 a delay due mostly to shortages of optical quality glass. It was manufactured solely at the RFC repair depots in France and was developed to satisfy the requirement for high resolution oblique photography. This was an enlarged version of the Type A using 81/2 X 61/2 inch plates and a means of fitting longer lenses through the use of a metal tubular extension to the main body of the camera of up to 20 and 40 inches. Most of the first B Type cameras were constructed using captured German camera lenses. The Type B illustrated has been fitted with a semi automated plate changing mechanism.


Type B camera with changing mechanism © IWM

AERIAL PHOTOGRAPHY, FIRST WORLD WAR 
Type B camera fitted in a FE2 © IWM (MH 33756)


Monday, May 16, 2016

British Photographic Reconnaissance Cameras in WW1 - Part 1

The following posts look to build on those covering ‘British Aerial Photography and Photographic Interpretation on the Western Front’ by adding detail around the development of aerial photographic cameras.

TYPE A

Following the establishment of an RFC experimental photographic section in the middle of January 1915 one of the first tasks was to design a purpose built aerial camera. The Royal Flying Corps embarked on a series of aerial photography cameras with an alphabetical designation starting with the Type A. This was first used over the German lines on 2 March 1915. The Type A was designed in conjunction with and manufactured by the Thornton-Pickard Camera Company. They were well known as suppliers of craftsmen made wooden cameras for studio and general photography. The Type A was constructed of wood. It had a square tapered body with a fixed focus 8 inch lens set at infinity focus. There were two versions of the body, one with dovetail jointed corners, the other with reinforced corners made of wooded strips with the grain running at right angles to the main body panels. Brass reinforcing strips and corner pieces varied also between the two versions. The weight of this camera with the 8 inch lens was about 10 lbs.

Thornton Pickard A Type camera 
Thornton Pickard A Type camera © IWM (PHO 61)

Five by four inch plates were adopted for the negative materials, first in double dark slides and then later in the Machenzie-Wishart envelopes and holders. The shutter was of the single blind, Goetz pattern, focal plane type. This shutter, since it had no capping blind as incorporated in later types, required the fitting of a lens capping plate in the body to prevent light reaching the negative material during the rewinding of the shutter blind when the exposing slit moves back across the focal plane.


Observer in Vickers FB5 receiving an A Type camera

The main controls were a shutter winding knob, shutter release which also moved the capping plate just prior to the exposure and a shutter blind spring tension adjuster. The controls were interlocked to prevent accidents to the routine procedure. The standard Type A was used for both oblique and vertical photography. For the former a tube and crosswire viewfinder which could be fixed above or below the camera was supplied. Straps were fitted to the sides of the camera for the observer to grip as he leant over the sides of the aircraft to take the photograph. For vertical photography, the camera was later mounted on a wooden frame attached to the side of the aircraft. The chief shortcoming of this piece of equipment being the complexity and effort entailed in the changing of the plate. Each plate had to be changed by hand a process that requiring 11 distinct operations; many plates were ruined by clumsy handling with frozen fingers. Lieutenant Sholto Douglas an observer on 2 Squadron described some of the first experiences with hand held cameras:
  • "We found that, by cutting an oblong rectangular hole in the floor of the observer's cockpit of a BE 2a, the observer could, if he was not too bulky, point a camera downwards between his legs and through the aperture, and thus get a (more or less) vertical photograph. It did not occur to us to fix the camera in the floor of the cockpit. …... We then went up to try and get some photographs of the trench system on our front. I found that the chief difficulty was that when the camera was pointed through the aperture in the floor, one could not see the ground at all, so I had to get my pilot flying on a straight and level course at the object or area that I wished to photograph; hold the camera clear of the aperture until the area to be photographed nearly filled the said aperture; and then pop my camera down into the hole and take a snap shot. This procedure was not too easy in the cramped space available, especially as the weather was cold and bulky flying kit a necessity. Each plate had to be changed by hand; and I spoilt many plates by clumsy handling with frozen fingers.”



AERIAL PHOTOGRAPHY, FIRST WORLD WAR 
Caudron G3 with an A Type camera fitted to the fuselage © IWM (HU 91040)

Operating limitations, the need to lean out of an exposed aircraft cockpit and operate a camera that required eleven distinct operations for each exposure with thick gloves or numbed fingers, combined with the need for vertical photographs for mapping purposes, led to the fixing of the camera to the aircraft.  This was only possible when the key challenges of distortion due to aircraft movement and vibration caused by the aircraft motor necessitating fast shutter speeds, 1/125 of a second, were overcome.  By the summer of 1915 when the ‘C’ type camera became available fixed semi-automated aerial photography had been achieved.


Next Part 2: B and C Type Cameras

Friday, August 29, 2014

The Battle of Mons - 23 August 1914

New to the battle of Mons? Listed below are a variety of resources that will provide you with an understanding of what happened during the British Army's first engagement of the First World War:

Webpage: The Battle of Mons - The opening battle of the First World War for the British Expeditionary Force.

Video: BBC Series 'Our World War' Episode 1 - The defence of Nimy bridge by the 4th Royal Fusiliers in August 1914.




Podcast: The Road to War Episode 9 - The Battle of Mons Dr Brett considers the battle of Mons (one of a series of podcasts from a team of historians from the University of New England)

Podcast: Imperial War Museum Podcast 7 - Into Battle. As soon as the First World War broke out in August 1914, men from across Europe were sent into battle. Listen to some of them recall what they experienced – fighting on land, in the air and at sea – in the first month of the war.

Books: Low cost Kindle Editions

The Great Retreat of 1914: From Mons to the Marne [Kindle Edition] - More recent historical perspective. (£1.99)





FROM MONS TO THE FIRST BATTLE OF YPRES [Kindle Edition] - The first hand account. (£0.77)





Over by Christmas: The Retreat from Mons [Kindle Edition] - Historical fiction. (£1.53)







Books: Historical narratives - free from the Internet Archive

The first seven divisions : being a detailed account of the fighting from Mons to Ypres - published in 1916.

Official History: Military operations, France and Belgium, (August to October) 1914 - published in 1937.