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