Colour Correction and Colour Grading

Colour Correction

• Colour correction is the process of manually changing such things as colour temperature, (also known as white balance) and exposure amongst other things. Because filming is never going to be perfect, this is a necessary stage, as it will make the end product of all the scenes look more professional.

However, it is usually considered that shooting flat will give more room to move in post-production. Shooting flat means having as little-in camera processing on the image when filming. An easy way to colour correct is to use the fast colour-correct effect in Adobe Premiere.

When colourists are editing a movie to get the perfect correction and colour, they watch it in a cinema while doing so to get an actual sense of what the audience would be seeing in a cinema. The colour correction technique has to be seamless, not different colours or saturation in each scene. Furthermore, they can make certain scenes that were shot in the evening look like it was shot in the afternoon or scenes that were shot earlier in the day, look like nighttime shot.  They also play the score/soundtrack while editing this to see if the colours match the mood of the music, for example, a happy, uplifting song would require warmer tones in the scene.

Colour grading refers to making further alterations after correction. This stage is not seen as correction mistakes, but more as adding style to the footage. By selecting the colour correction in Adobe Premiere, there is an option to use scopes and waveform that give a visual aid to the changes being made.

The Process

1. Edit the footage into a sequence and remove any noise or artefacts that are not wanted in the footage.
2. Correct the colour temperature (white balance).
3. Adjust the blacks (shadows) and the lights.
4. Adjust the mids (every colour but black and white) to make sure that things such as faces stand out. This can be done using the 3-way colour corrector effect.
5. Add any appropriate filters, this is no longer correction, but instead grading.

Lookup Tables (LUTs)

A LUT (Lookup Table) is essentially the modifier between two images, the original image and the displayed image, based on a mathematical formula. There are different types of LUTS – viewing, transform, calibration, 1D and 3D. The three colourists go into a lot of detail on all them.

Adjustment Layers – Layers that will lie over the entire film (or entire sections) to alter on a larger scale. This can include such things:

• Colour presets
• Exposure presets
• Film grain
• Vignettes
• Distortions