Apple Color 1.0 - Manual (Page 19)

Chapter 1 Color Correction Basics 19
Color Timing for Film
Programs being finished and color corrected on film traditionally undergo a negative
conform process prior to color timing. When editorial is complete, the original camera
negative is conformed to match the workprint or video cut of the edited program
using a cut list or pull list (if the program was edited using Final Cut Pro, this can be
derived using Cinema Tools), which lists each shot used in the edited program, and
shows how each shot fits together. This is a time-consuming and detail oriented
process, since mistakes made while cutting the negative are extremely expensive to
correct.
Once the camera negative has been conformed and the different shots physically glued
together onto alternating A and B rolls, the negative can be color timed by being run
through an optical printer designed for this process. These machines shine filtered light
through the original negatives to expose an intermediate positive print, in the process
creating a single reel of film that is the color-corrected print.
The process of controlling the color of individual shots and doing scene-to-scene color
correction is accomplished using just three controls to individually adjust the amount
of red, green, and blue light that exposes the film, using a series of optical filters and
shutters. Each of the red, green, and blue dials is adjusted in discrete increments called
printer points (with each point being a fraction of an f-stop, the scale used to measure
film exposure). Typically there’s a total range of 50 points, where point 25 is the original
neutral state for that color channel. Increasing or decreasing all three color channels
together darkens or brightens the image, while making disproportionate adjustments
to the three channels changes the color balance of the image relative to the
adjustment.
The machine settings used for each shot can be stored (at one time using paper tape
technology) and recalled at any time, to ease subsequent retiming and adjustments,
with the printing process being automated once the manual timing is complete. Once
the intermediate print has been exposed, it can be developed and the final results
projected.
While this system of color correction may seem cumbersome compared to today’s
digital tools for image manipulation, it’s an extremely effective means of primary color
correction for those who’ve mastered it.
Camera Negative Conform Negative Optical Color Timing Final Film Print