Day 330: CSO Sole

Special FX done the old-fashioned way…

November 26 main

Welcome to CSO: Sole. That’s CSO not CSI, though back in the ’70s CSO did leave a blue halo around objects like a cobalt version of those chalk outlines you see around people in crime shows. It stood for Colour Separation Overlay, and was en electronic effect (ie, it could only be achieved on video) used by the BBC in the ’70s and ’80s that was a quick and easy way of “cutting out” one image and overlaying it on another. The object that needed to be “cut out” was shot against a blue (or sometimes yellow) background and that background colour could then be made invisible before the object was combined with a background. (This has, of course, developed into the green screen work we see today).

Alternatively, as in the shot above, the “view screen” would actually be a solid blue (or yellow) and another image to be inlaid into it.

Except, the effect was rarely invisible. Apart from the blue (or yellow) halo, often the blue or yellow background would cast a blue or yellow hue on any objects or clothing in the vicinity. Which is why the Cyberman above has blue shoulders; he’s reflecting the blue from the actual screen, rather than the image overlaid onto it.

(As a side note, Doctor Who often opted for yellow screen rather blue screen work because the TARDIS was blue, and so if it were in a CSO shot where blue was the colour that would be matted out, it would have vanished even when it wasn’t supposed to!)

Anyway, that history lesson over, I can tell you I’m still pissed off that TalkTalk hasn’t fixed my internet, Im still using my iPhone to tether my laptop to the internet, which is still glacially slow. To be honest, I can’t recall if I’ve used this Cyberman image before (I don’t think so) but it would currently take an age to search through previous SOSF blogs to find out, so I’m hoping I haven’t.

So the moral of today’s episode is, don’t sign a contract with TalkTalk.

See you tomorrow!

Donate buttonUsual Begging Sign-Off

• Current total: £1,300 

• Remember this is all for charity, so any pennies or pounds you can spare PLEASE DONATE BY CLICKING HERE.

• Follow me on Twitter to make sure you see what trainers I’m wearing each day.

• If you have any trainers you could donate (either on loan or old pairs you’re getting rid of) which are size 9 (ish – I can do anything  from 8 to 10) contact me at so I can arrange collection.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s