black and white level

[Eric Jurgenson]

Composite video (with 100% white levels) is 1 volt peak to peak, including sync. Sync goes from 0 volts (blanking level) to negative .3 volts. The actual video signal (including blanking) goes from 0 volts to positive .7 volts. Frequently this is expressed as IRE units, where blanking is zero, black is 7, white is 100, and sync is -40. So there are 140 IRE units in a 1 volt peak to peak composite video signal.

So you are correct. Adobe has gotten it wrong. They are assigning 0 volts to the sync tip (the correct value is -.3 volts) and black to .3 volts (the correct value is .05 volts – 7 ire units above blanking, which is 0 volts)

Perhaps they should stick to IRE units and forget about voltage.

[Peter Crawford]

Just gone back to premiere fro fcp and trying to get my head around thier scopes.
How can I grade if these scopes are wrong? If everything is wrongly clamped T .3?

Thanks
Peter

paxpincer