"TA" is the current doping scheme, British Aeroplane Varnish Co. 'TITANINE A'. Later marked on the rudder stripe.
"RA" was Royal Aircraft Factory A. "CA" was Cellon Ltd. A. "EA" was British Emaillite A.
The device is a Type "C" aerial camera, must have slowed the aeroplane down somewhat.
Nick
https://en.wikipedia.org/wiki/Aerial...nce_camera.jpg