Zone System / Waveform monitor relationship

[EDDUS RAY]

Does anyone have any information regarding the application of the Zone System to the waveform monitor? Do certain Zones fall over IRE brackets? I.E. Zone V @ say 50 IRE'S...?

Edited August 26, 2012 by Judson Lee

[Phillip Jackson]

From my understanding no, that's not the case. IRE is a percentage based value for the video signal being broadcast and since each camera has a different dynamic range the values shown by the IRE will relate to each dynamic range differently. You'd have to do tests with a grey scale (with your shooting camera) to really be able to know how to read the IRE values in stops. This isn't even considering the fact that IRE are logarithmic and not linear so it won't 6 IRE = 1 stop throughout the waveform.

[EDDUS RAY]

From my understanding no, that's not the case. IRE is a percentage based value for the video signal being broadcast and since each camera has a different dynamic range the values shown by the IRE will relate to each dynamic range differently. You'd have to do tests with a grey scale (with your shooting camera) to really be able to know how to read the IRE values in stops. This isn't even considering the fact that IRE are logarithmic and not linear so it won't 6 IRE = 1 stop throughout the waveform.

 

Thanks man, that make sense.

[Bruce Southerland]

There's an article in the American Cinematographer video manual 3rd Ed. titled "How to use the zone system to predict

Video image contrast", which discusses the relationship of IRE units and the zone system, if you can get you hands on

one. I bought my copy on half.com.

[David Mullen ASC]

The other issue is whether you are applying the Zone System concept to a Rec.709 signal or a flatter Log gamma, which would contain more or less the total stops of DR captured.