 # Oscilloscope Pt 2: Component Video Testing with Ste Here’s a continuation of Ste teaching us how to use an oscilloscope. This time we focus on testing component video testing, as well as brush up on our scope skills:

Here’s the full formula Ste used to calculate expected voltage differences:

The below only applies to standard defintion and enhanced definition resolutions.
i.e. 240p/288p/480i/576i/480p/576p

====================================

Everything is relative to peak luma (pure white).
First, measure white bar on Y using 100% Colorbars pattern and record it.
Calculate the other color values using the below equations.

Y:
yellow = 0.886*white
cyan = 0.701*white
green = 0.587*white
magenta = 0.413*white
red = 0.299*white
blue = 0.114*white

Pb:
yellow = -0.5*white
cyan = +0.168736*white
green = -0.331264*white
magenta = +0.331264*white
red = -0.168736*white
blue = +0.5*white

Pr:
yellow = +0.081312*white
cyan = -0.5*white
green = -0.418688*white
magenta = +0.418688*white
red = +0.5*white
blue = -0.081312*white

====================================

Example calculation assuming white is measured at exactly 700mV (as seen in the video).

Y:
yellow = 0.886*700mV = 620mV
cyan = 0.701*700mV = 491mV
green = 0.587*700mV = 411mV
magenta = 0.413*700mV = 289mV
red = 0.299*700mV = 209mV
blue = 0.114*700mV = 80mV

Pb:
yellow = -0.5*700mV = -350mV
cyan = +0.168736*700mV = +118mV
green = -0.331264*700mV = -232mV
magenta = +0.331264*700mV = +232mV
red = -0.168736*700mV = -118mV
blue = +0.5*700mV = +350mV

Pr:
yellow = +0.081312*700mV = +57mV
cyan = -0.5*700mV = -350mV
green = -0.418688*700mV = -293mV
magenta = +0.418688*700mV = +293mV
red = +0.5*700mV = +350mV
blue = -0.081312*700mV = -57mV

…and here’s the original how-to video: