What's Wrong With... Robot

Colour Separation Overlay works on the principle that objects of a certain colour, filmed against a backdrop of the same colour, can be keyed out and replaced with the output from another camera. Traditionally the key colour has been blue, though in more recent times green has been the favoured option. The phrase "greenscreen" has pretty much come to be the industry norm for this effect. When director Paul Bernard was coaxed away from ITV to helm a couple of Doctor Who stories in the early 1970's, Barry Letts wanted to pick his brains about the techniques which the opposition were employing. ITV favoured yellow as the key colour. As he had championed CSO at the BBC, Letts agreed that yellow should be used on Doctor Who - first appearing on Bernard's Day of the Daleks.

The main requirement of the key colour was that it did not feature too prominently in nature, and costume designers could be advised to avoid it - otherwise the bits of costume of that colour would appear invisible.

Robot required the titular creature to grow to enormous proportions in the final episode, so only CSO would manage this. Director Chris Barry was using Outside Broadcast video to record the location scenes, and this worked better with CSO. When objects recorded on video were superimposed onto film, they had a tendency to appear to float, and did not integrate properly into the composite image.

The problems with CSO should have been minimal for this story - but no-one had thought about the fact that the robot was made from aluminium. Shiny, reflective aluminium...

When the robot grows, its legs begin to vanish, along with other bits as they reflect the key colour.

(NB: the DVD and Blu-ray versions have had this problem rectified to some extent).

CSO also allowed for cheaper productions, with sets and props made model scale and simply superimposed onto the background. A real army tank would have cost money to borrow, along with limited access. Letts advised using a model - and the one they went for wasn't one constructed especially by the VFX department. They used an Action Man tank - and it looks like it. The toy lacks any sort of detail, and has tracks which don't match a real vehicle. The VFX team should have been asked to adapt it, by adding detail, but this didn't happen. Had it been filmed slowed down it might have looked better, but it is on video in real time. 

What makes this worse, is that the tank features in the Part Three cliff-hanger - so you get to see it all again the following week.

The little Sarah doll looks exactly like that - a small doll. When the robot places her on the roof, there is a CSO mismatch as she is supposed to be gripping a drainpipe - but misses by a couple of inches.

The height of the robot varies in relation to the background. No-one has thought to properly work out the scale.

Michael Kilgarriff had a terrible time in the costume. Despite lots of padding at the joints, he was badly scratched and cut. One night he had a nightmare about being trapped in a miniature submarine, and when he tried to get up the next day he found he couldn't move his legs for a few hours. There is an actual trip captured on screen, after he has broken out of Kettlewell's laboratory, and we see an almost trip as the robot descends the steps outside the SRS meeting.

On leaving the meeting, Jellicoe hides behind the robot - but UNIT troops could have easily shot him at any time. They're too busy pointlessly shooting the  robot.

The Doctor claims to have the Freedom of the City of Skaro. This must be a Thal settlement, as the Daleks would hardly be issuing such things. He also mentions that the Alpha Centauri table-tennis team use 6 bats, as they have six arms. A two armed person only uses one bat - not two - so either he's confused or they play a totally different version of the game on Alpha Centauri.

The SRS object to Sarah wearing trousers - despite these being the most practical - and rational - form of dress for both men and women. They should be objecting to impractical skirts instead.

Does skirt-wearing feminist Miss Winters know that her underlings are advocating this sexist dress code notion?

The man objecting to Sarah' dress is played by Timothy Craven - who previously played the chap who moaned about having sold his house to travel to another planet in Invasion of the Dinosaurs. They missed a trick by not having him the same character - driven to join the fascist SRS after being duped by the equally fascist Operation Golden Age.

The SRS people at the meeting are shocked to see the robot for the first time - and are then informed that UNIT are on their way to arrest them all - yet they stop to laugh at the Doctor doing silly dances and tricks. Terry Walsh's bouncer  - who the Doctor previously tripped up - is then seen simply standing back, arms folded, watching the same on stage antics, and needs prompting to try to stop the Doctor.

Much of the story revolves around the theft of components for the Disintegrator Gun. As it was developed by Think Tank, this simply draws attention to the organisation. After they get the Gun, they simply use it to open a safe, and it's the launch codes that they are really after.

Even in 1975 this bunch of scientists ought to have known what a nuclear winter might have looked like, so it is bizarre that Miss Winters insists on triggering the missiles. How many of her supporters actually made it into the bunker anyway, to create her new society?

UNIT aren't any smarter, what with them managing to lose a 9 foot tall robot in broad daylight.

Kettlewell's virus was designed to devour all metals - not just the robot's special alloy - so I hope the Doctor adapted it in some way before he released it into the atmosphere of south-east England...

When the Doctor chops a brick in two, it clearly sounds like a block of wood instead.

We see the opening section of the note which the Doctor leaves for Sarah - and when she reads it back later it isn't the same.

The BBC was undergoing one of its periodic strikes - this time involving the scenic crew. Keep an eye out for a ladder that appears in the background in a number of scenes. The crew were not allowed to touch it so they just filmed around it.

Finally, don't expect this story to represent the start of a new era, even if there's a new Doctor. It is actually the end of the old one, recorded back-to-back with Planet of the Spiders. It is a Barry Letts-produced, Terrance Dicks-written, UNIT story, so has much more in common with Season 11 than with Season 12.