For that matter, does anyone know of the origin of the Short Granite image?
The image no doubt is from the late Lorna Arnold's book "Britain and the H-Bomb" as other declassified images of the other thermonuclear test-devices I don't know if there are any however it is very likely that they used identical radiation-cases to that of the Short Granite device in order to keep variables to a minimum (And hence fewer tests).