last updated 8 Apr 2007

DI - Grading

Digital Intermediates - Grading the film

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Grading - the heart of the DI process. This is where the film takes on a new "look"




Grading is the heard of the film DI process. It is for grading that people do DI in the first place. Scanning and conforming which precede grading are processes that set up the grading process.

Grading is done on a conformed timeline which is an accurate reconstruction of the edit done by the original editor but at film resolution. The film colourist (as the grading pro is called) takes this timeline of shots, under the supervision and direction of the film's cinematographer of DOP (Dir of Photography) goes over the whole film and 'colour corrects' it.



If you're not familiar with this conform process, go over to my DI-conform page first.

If you are totally unfamiliar with DI or Digital Intermediates, then please read my DI-basics page first.

Why grading?

But why does one need to 'colour correct' a film? Well, for one thing there are minor differences in colour rendition between shots in a acene and between scenes. These need to be ironed out and balanced.

But even more important, is that it is possible, with grading in film DI, to give the film a look that adds to the impact of the story.

You can give any scene or shot a completely different feel than was originally shot. Or just enhance the feel that cinematographer designed through his lighting. If editing is the second time the film is directed, then grading is the second time a film is filmed.

Another reason for grading using the DI process is if a film has visual effects or animation. These visual effects scenes will be digitally created or composited anyway, so it makes sense to make the entire film digital so it balances out.

Yet another reason is format. If the film is shot using 16mm film, then it needs to be eventually blown up to 35mm to be shown in theatres as no commercial theatres have 16mm projectors. The DI process does this 'blow-up' digitally.

Or if the film is shot on Super35 and needs to be printed out as 35mm Cinemascope. The DI process does this digitally.



How does it work?

Films have been graded optically for many decades. So DI film grading is a process that enhances an existing process. Traditionally films have been graded on an 'analyzer' which is an optical devices where one adjusts colours by actually adding filters.

Analyzers offer adequate colour correction control in a film. But they do not permit precise controls of a single colour without altering other colours. They also do not permit control or correction of a part of the frame.

That's what's done by film grading systems like Autodesk Discreet Lustre, Quantel, iQ, Baselight, Nucoda Film master, DaVinci Resolve, etc.

All these systems have the the same basic components.
1. A computer running WinXP, Linux or some other OS.
2. A 'console' or special purpose panel that has many buttons and knobs. The colourist actually oerates this and the colours change.
3. A monitor to show the actual grading interface. And the film image.
4. A projector which shows a large image so the colourist and DOP get a more cinema-like feedback.
5. Calibration system which ensures that the picture on the screen is exactly or nearly what will show up after the image is recorded back to film and printed.
6. Large darkened room like a mini theatre so the cinema atmosphere is complete.

With the exception of systems like Quantel iQ and maybe Film master, the grading process is silent. Most grading systems are not capable of reliably playing back sound whilst grading. And even if they did most DOPs would switch sound off since the continuous back and forth of image with sound might get annoying.


Grading Systems    
in alphabetical order    
Assimilate from Scratch    
Baselight from Truelight    
Bones from Thomson    
Clipster from DVS    
Film Master from Nucoda see also Film Cutter and Data Conform    
FinalTouch 2k from Silicon Color see also FinalTouch HD, FinalTouch SD    
Fstop from Edifis    
iQ from Quantel see also Pablo    
Lustre from Autodesk Discreet    
Resolve from DaVinci    
SpeedGrade from Iridas    

This is page is incomplete. I'm still working on it so please come back and check. But do return, it won't be long.







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