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:
Auto Amazon Links: No products found. http_request_failed: A valid URL was not provided. URL: https://ws-na.amazon-adsystem.com/widgets/q?SearchIndex=All&multipageStart=0&multipageCount=20&Operation=GetResults&Keywords=B012938E76|B00NAATDEG|B00MJDC2M0&InstanceId=0&TemplateId=MobileSearchResults&ServiceVersion=20070822&MarketPlace=US Cache: AAL_39dfc853132bb07969d09dc755185342
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:
Follow HDRetrovision on Twitter:
#hdretrovision, #ste, #oscilloscope, #ypbpr
