Election 74

Yes - vertical blinds or some toblerone type physical unit usually, with one side painted a CSO (or Chromakey for non-BBC viewers) colour - usually blue in the 70s (green is used these days because with 4:2:2 you get more HF detail and bit depth from green and thus a cleaner clip, but with analogue RGB blue was as good)

The other thing to remember is that in the early 70s there wasn't anyway of electronically re-sizing and angling a picture - DVEs hadn't been invented (Quantel introduced the corner shrink around 1976) So if you wanted a "virtual" screen keyed into your picture, you also had to point a camera at a small studio monitor and frame the camera pointing at it to match the "hole" in the studio shot! (And make sure that nobody walked between the camera and the monitor)

Looks like I got the years mixed up, it was 1979 that featured NODDY clock during Sue Lawley's news bulletin



Would that have been fed from pres or would they have set up a spare model in TC1?

Thanks for the answers to my question about they chromakeying.

All very interesting stuff, and I didn't realise how long the technology had been around for. It was pretty convincingly done on the election programme. Despite them using toberlone-style set/screen, it all lined up very well and you couldn't see any gaps in the picture when it wasn't transitioning on or off. A very nice effect.

Believe it or not, there was an experimental chroma-key camera made for black and white TV. It had two tubes, one conventional monochrome tube (that would have been found in any normal B&W TV camera of the time) and a second tube that was filtered or sensitive to one particular colour. That second tube gave you a key signal - so although the show was B&W you could use a coloured bit of set to generate a key signal to insert a second B&W image.

On a previous repeat of the February 1974 election programme (which used the same set as in Oct 1974), they showed the transition of the screen: but the keying failed . . . so the view was simply the 'blinds' turning from grey to yellow.

How quaint.

I'd have thought it would have been tielined from pres down to tc1, relatively easy to achieve. They'd not only have had to set up a spare clock, but also a 'Cox Box' to colour it blue and yellow. Mind you I doubted on this very forum that they set up a double level election studio in TC6, where the presenters and cameras were working literally on top of the journalists who were on the studio floor beneath them, yet that proved to be true in the end, so maybe the BBC had form for never taking the easy option!

PEDANTRY ALERT: It was actually a different set in February, there was a different scoreboard and the big "screen" and Robin Day were both to the left of the studio, as we looked at it, as opposed to October where they were on the right.

Yes - Yellow was used on occasions ISTR. I think I've seen the odd bit of yellow fringing on Doctor Who CSOs in the past.

I know little about television technology, so pardon my ignorance, but since (Caucasian) skin tends to be yellowish in tone, wouldn't yellow-based CSO bleed through on people's faces? (Meteorologists are instructed not to wear anything remotely green when using a green screen, for instance.)

Who said anything about CSO-ing humans

Star Trek TNG IIRC used chrome orange for much of their model filming, which then meant they could include green and blue elements in the designs.

I see -- but that would have effectively excluded any light-skinned humans from those shots, right?

They used quite a bright yellow, so unless your programme was being presented by the Simpsons, then I don't think the talent would have been affected.