Color Correction and Visual Effects

[Jeremy Montana]

Seems like it might be a silly question, but which is done first?

 

Is it better to correct the full image with effect finished, or correct the image to the proper look and then let the SFX guys match up the elements?

 

Thank you.

[Will Earl]

It depends...

 

Typically a neutral grade (a basic colour correction to bring all the shots into line) is created and these plates are worked on for VFX. If the colourist has a look for the scene while the VFX shots are being worked on - an additional LUT can be given to VFX to show what the final grade will look like - but the completed effects will be delivered as neutral. Obviously there are plenty of cases where the VFX need to actually do some grading in order to create a shot - for example a day-for-night shot, but in these cases the shot will still be kept rather conservative as far as the grade goes.

 

The 'creative' side of colour correction is mostly done in the DI.

[Paul Bruening]

I often suspect when seeing mediocre CG that insufficient interactions between the geeks and the colorist has occurred. Poor color matching is number one on my list of bad CGFX (bad action matching is #2, bad character motion, #3, bad texture matching, #4). I imagine the workflow being disjointed and unconnected; a lack of adequate "dancing" as a significant factor. This is a strong workflow example of an unavoidable "chicken or egg".

[Will Earl]

Paul,

 

It is one of those things where we try to handover shots where it is possible to push the grade in any direction and not have separate elements in the image 'colour-drift' (this is a term I've just made up right now) - where perhaps the colours don't match and adjusting the grade will show (for example) that maybe the black levels on the foreground element are different from the background element. Adjusting the gamma up and down to extremes is normally a good way to check if things are matching. As VFX and DI can be very separate processes on a production.

 

Still grading related, slightly different note. The plates on the show I'm working on now have been shot very low light, so we're having to finish shots where the image can be pushed up a stop or two and not break down completely - almost under the assumption that they'll brighten everything up in the DI. Only on a few shots do we have LUTs to see what effect the final grade will likely have - mainly because they're day-for-night.

 

-W

[Juha Leminen]

Correct way is to do FXs first and then do color work, if you think about it technically.

Like what happens to your cute or beautifull pixels and so on.

And hopefully the fx artist or artists has some eye for colors too :), well

so its still workable.

 

Juha

Edited December 18, 2008 by Juha Leminen