There are three common reasons why color bars would not be hitting the targets on a vectorscope:
1) If you are using 75% color bars and the vectorscope is configured for 100% bars, the color vectors will appear to fall short of their targets. Alternatively, if you are using 100% bars and the vectorscope is configured for 75% bars then the color vectors will appear to exceed their targets. The exact procedure for setting color bar targets on a vectorscope will depend on the model but is usually achieved through some form of configuration menu. The current target percentage setting should always appear in the lower right corner of the vectorscope display.
2) If you are using SMPTE color bars there will be many additional lines on the vectorscope display that may be confusing. Among these lines however you should see a set of lines that correspond to the 75% color bars contained within the SMPTE bars (approximately the top 2/3 of the SMPTE bars display) signal hitting their targets correctly.
3) If your signal is improperly terminated the voltage amplitude may become too high or too low which will cause the vector display to miss the vectorscope targets. If your signal is under-terminated or not terminated at all you will likely see the lines exceeding their targets whereas if your signal is over-terminated or double terminated you will likely see the lines fall short of their targets.
FAQ ID : 56241View all FAQs »