The Mk 1V Low Angle Gunnery marking camera.
The film was wound across the camera and gave an image of 8" x 2¾"
It was fitted with a prism for throw off shoots and featured a Louvre shutter
( Mk 111 at Hist1415)

Original Reference:
Date / Date Range: c1938
Submitted By: Roy Penny - included in his course notes (Hist1413)
Now Held By: Historian
Date Added: 24-11-2018
Historians Number: Hist1416
Original Website Link