View Full Version : What is 'film grading'?


Ted Bragg
June 26th, 2003, 05:35 PM
I'm hearing this more and more, a term called 'film grading'. An episode of Farscape featured trees and grass that had blue leaves and flowers instead of green. They said the film was 'graded' to achieve that look in post.

Another: matching CG characters into their live-action enivroment...the CG is said to under-go film grading to match.

Ummm...how is this done? Is it a developer's trick on film, or something done on computer?

Can film grading be used on DV shot footage?

Robert Knecht Schmidt
June 26th, 2003, 05:57 PM
"Is it a developer's trick on film, or something done on computer?"

Yes.

In the old days, this was simply called "color timing," and the color tone of the developed film was proportional to the amount of time the film spent under a filtered printing light.

These days, professional color timing is getting the digital treatment, and a variety of expensive new hardware products are coming onto the market. Most of these are systems that only post houses can afford, for example, discreet's lustre (http://www.discreet.com/products/lustre/), which was demoed at Cannes this year. This system is capable of amazing ouput, and is streamlined for superfast workflow.

"Can film grading be used on DV shot footage?"

Laboriously and brusquely, using tools available for After Effects, combustion, and the like. But DV is 24 bit and you won't have anything near the tonal subtlety of film to play with as far as dynamic range goes. (lustre operates with 48 bit precision data: ~16.8 million times as many colors.)

A great example of a movie originated the old fashioned way on chemical film stocks but digitally graded to achieve the cinematographer's desired look was O Brother, Where Art Thou?, shot by Roger Deakins.

PS
Welcome to the DVInfo.net Community, Ted!

Rick Spilman
June 26th, 2003, 06:13 PM
In the interview and commentary she did on the "Personal Velocity" DVD, Ellen Kuras, the film's DP, commented briefly on how the color timing of a DV feature was different from the typical 35mm feature. After color correcting each frame of the film in post she sat with the folks who took the video to film and made sure that they got the color timing right.

Interesting discussion, even if I only understood the broad outlines of what she was talking about.

Rob Belics
June 27th, 2003, 07:29 AM
Color timing does not involve time spent in the chemical bath. Color timing is done by a colorist who will use various filter combinations to balance or touch up the print. Digital grading is done by digitizing the film and adjusting the colors there. It is more likely to be used if the film has a lot of cg effects because it's easier to match the differences between film and digital inputs.

Robert Knecht Schmidt
June 27th, 2003, 11:15 AM
Thanks for the correction, Rob.

Not technically a part of color timing, but popular processes that do effect the color of film in the chemical development stage, are the skip-bleach (or bleach-bypass) and ENR silver-retention processes used to imbue with grit and muted hues films like The Cell and Saving Private Ryan.

Other processing tricks like VariCon and Push/Pull also effect contrast, grain, etc.

Quiz: who knows exactly what ENR stands for?

Rob Belics
June 27th, 2003, 12:54 PM
If I remember right, enr is the company that designed it or the guy who invented it.

Jeff Donald
June 28th, 2003, 09:56 AM
ENR are the initials of the man that developed the technique while he worked for Technicolor in Italy. If I remember correctly it was developed for the film Reds.

Robert Knecht Schmidt
June 28th, 2003, 10:11 AM
Very good, Jeff, getting warmer...

Ernesto Novelli Rimi developed the variable silver retention process at Technicolor Rome for Storaro's 1981 film directed by Warren Beatty. Storaro would go on to play with shades of color shooting Tucker: The Man and His Dream and Dick Tracy...

David Warrilow
July 3rd, 2003, 09:39 PM
There's also a nice little intro to digital colour grading on the Lord of the Rings - 4 disc set. They're sitting there using a 5D collossus (I think) and going through some of the changes and variations they used on the film. 2K plate tracking, masking and colour correction all in better than real time. Impressive power.

cheers,

DW

Dave Valencic
July 5th, 2003, 12:17 PM
You can do "DV Digital Grading" yourself simply by using After Effects. I had zero budget for my last short film, and it badly needed some sequences color corrected (shot on different days, different lighting, etc,etc) and using some filters in After Effects like Curve, Hue/Saturation, Color Balance, and Brightness/Contrast you can do ALOT to change an image. Color Balance is great for controlling shadow and/or highlight colors.

I recently color corrected a skate video for a friend of mine (he shot it on Digital8) which had AMAZING skaters in it, but alot of the shots were badly colored (mainly due to the auto-white balence of the D8 cameras, although his was hacked to give manual white balence... well not really, but it let him select indoor, outdoor, and hold)

If I can find them, I'll post some before/after shots of what is possible in After Effects as far as grading.