Crossroads One Hour Special - TONIGHT at 5! (4.30 N Ireland)

Colour Separation Overlay, also known as ChromaKeying depending on who you work for

It's how things like weather is done, shoot against blue screen, electronic wizzardry replaces the blue with whatever you want.

Sorry to be a pedant, but these days, blue has generally been dropped for green, as blue has become more common in clothing than it used to be.

I remember a couple of years ago, I was CSO'ing Sandy Gall, who chose to wear a green tie!!! You'd think he would have known better!

DG

Well in that case, you can key any colours.

Blue and Green are chosen as they aren't close to skin colour. The problem with green is that if it's not correctly set up for hue and key amount etc. you will end up with a radioactive green glow around people, if you adjust the amount to key, you could end up taking away some of the person or his/her clothing.

Although it does mean people can wear blue!

CSO is a very BBC term though, the correct term that applies to everyone "Chroma-Keying". That's generally what you find on all vision mixing desks, well the GVG and Sony ones I've seen.

"Luma Key", "Matte Keys" are also available in the interests of fairness

And for those very technical "Downstream Keying" also exists, but this is slightly different.

I still can't wait to see how UTV are going to get round the central-based presentation... check tonight's "Coming Tomorrow" trails... you might just see a "Not available on UTV" sticker on the Angry Beavers trail.... (not!)

It it the same as the virtual CN West studio though?

do you mean is the virtual studio cso?

i understand it to be just a more sophisticated version of CSO - but the same principle (im prepared to be told otherwise though)

i think the virtual studio has a green background and a blue background - depending on the presenters clothes (i presume that as ive seen green dresses and blue ties) the desk in real life is brown - overwhich the virtual desk is keyed.

The Central News West 'virtual' studio is ALL blue, even the desk. You are correct tvmercia, it is a more advanced version of chroma-key but i forget what it is actually called

are you sure?, i captured this mistake about a year ago - which makes me think it is a brown desk in reality.
http://www.andrew986.clara.co.uk/CNvirtual.jpg

Red is also commonly used for CSO... but it does tend to bleed .

I would only use red for when no other colour is available for keying say, in graphics etc. but then you could just use a matte.

When it comes to things like virtual sets, you wouldn't use red, because it's too close to flesh colours, and without decent lighting and equipment, you could end up with an invisible presenter.

The more advanced version of chroma-keying is "Chromatte" which is the grey background, and camera with little blue LEDs round the lens.

The desk can't be blue, infact it probably isn't, otherwise it woudln't show up at all on output. tvmercia's picture shows this clearly. The bits with the Central News orange logo are the bits that were blue for keying and the actual desk is clearly brown.

Back to the point of this post, does anybody know how UTV will disguise the fact they're leaving CITV 30 minutes early?

Let's hope the ep was sent down to them problem free.