Quote Originally Posted by tylerr
I understand that it needs to be a lot of parameters so is it a control limitation?

Tyler
Have you ever tried to do a useable key - even with professional equipment - and the best software?

Its a nightmare....and users would complain the whole time "Its not good enough"

Keying on colours - any colour - is a nightmare.

'Colour' isnt just 'colour'.

Its a research project in itself to get this stuff right.
And their are many many psychological factors at work.
( we read things as continuous colours, where in reality -- there are many many shades caused by shadows, lighting, viewing angle )
The computer cant read the users mind.
The users might think he wants something - the computer cant know what the user wants.
The computer has to interpret the information using a way which is not compatible with the way we perceive colour, or the visual experience of colour.

People are used to seeing professional and seemless compositing - but they dont see the effort and fiddling, which goes on to make this happen.
Nor do they see 'Shake' or whatever at work - in non-real-time with a whole stack of filters trying to extract foreground and background information, smoothly and visually pleasing.
As a last resort ( or even first resort ) on many shoots, people hand draw masks- because its easier to do this than correct anything a computer does automatically.