Origins of the 405 line system.

[ppppenguin]

I think the first British camera tube to have decent black level performance was the post-war CPS Emitron http://www.tvcameramuseum.org/emi/3lens/p5.html

Earlier tubes were high velocity types that suffered all the usual problems.

My copy of the Black Book has handwritten notes that suggest the fade time was reduced from 2.5s to half a second, though by what date I have no evidence. This may have been some fine tuning of the mixer system plus improved operator skills. I don't have any evidence that lift controls were added on a per camera basis but that doesn't mean it didn't happen. The producers of the time must sorely have wanted to be able to do cuts, for purely artistic reasons.