Painting HD Cameras – Basic Colorimetry

Ben Cain explains how to use test charts to not only match cameras but to paint looks into footage recorded using a Panasonic HDX900. Many of the principles in this article apply to other cameras as well.

Painting HD Cameras

In this article we are going to use the video camera’s Linear Matrix (also known as Matrix Table or User Matrix) and Multi Matrix (also known as Color Correction) menus to modify its colorimetry, which is the way the camera renders specific colors within its video color space which for HDTV is ITU-Rec. 709.

In most Panasonic cameras, the Linear Matrix is referred to as User Matrix and the Multi Matrix is referred to as Color Correction. In Sony cameras, Linear Matrix is referred to as Matrix Linear and the Multi Matrix is referred to Matrix (Multi). As this is a Panasonic oriented article, from here on out I’ll be using the Panasonic nomenclature.

The combined use of both the Chroma toolset (explained here), the Tonal Response Controls, i.e., Gamma, Knee, Pedestal, and Detail Circuitry is necessary to really “paint” a HD camera. There are a ton of tools at your disposal in a video camera’s Paint menu and only through lots of trial and error and the use of a calibrated reference grade monitor can one learn to use them correctly.

In order for any of this to make sense one needs to know the nomenclature. Colors are referred to as Hues in engineering lingo and Phase refers to the relative position of the color as plotted by a line on the vectorscope. For simplicity, in this tutorial I’ll be referring to colors as “colors” and not “hues”. For describing a video camera’s colorimetry, Japanese engineers have come up with a way of describing the six specific color phase adjustments we can make and those are G-B, G-R, B-G, B-R, R-G, and R-B.

“B-R” is read as: Blue ADDED TO Red which affects all colors MOST NOTICEABLY Blue, LEAST NOTICEABLY Red. A positive value increases the Saturation of Blue added to Red. A negative value decreases the Saturation of Blue added to Red.

“G-R”, is Green into Red. “B-G”, is Blue into Green, etc. With B-R, you are adding or subtracting Blue into or from the Red channel. G-R, adds/subtracts Green to the Red Channel.

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