White 108, Black -8. Are they legal?

BittenByTheBug wrote on 5/13/2010, 3:27 PM
When I applied the Soft Contrast FX to a clip, the highlight reached 108 while the shadow got down to -8.

I have heard before that 108 can be legal in some cases, but have never heard blacks can go below 0. Since it looked like the Soft Contrast FX set these two numbers, does this mean -8 to 108 are the new tonal boundaries? Would like to hear some opinions from pros.

Thanks,
BBTB

Comments

GlennChan wrote on 5/13/2010, 9:18 PM
No.

2- The scopes in Vegas will show different things depending on their settings. And there is stuff in them that doesn't make sense, e.g. if you have the 7.5 IRE setup box checked, there is no marker line at 7.5 to help you judge black level.
They aren't really a helpful tool to help you figure out your levels. (Unless you know what they are and then you know what settings to use... a catch 22. For some applications you will need external scopes.)

3- See the example workflows here:
http://www.glennchan.info/articles/vegas/v8color/vegas-9-levels.htm

On top of that, you can add the Broadcast Colors filter to deal with the illegal values.

Start with the conservative preset.
If your country is a NTSC country other than Japan, check the 7.5 IRE setting in the broadcast colors FX / use the 7.5 preset. Otherwise don't check it.
Check the studio RGB setting if your codec is expecting studio RGB levels.
TheHappyFriar wrote on 5/13/2010, 9:28 PM
i'd ask "what's your target?" on computers nothing is illegal. LCDTV's don't seem to care about illegal colors either, only CRT TV's.

So it may not even matter to you at all in the long run.
BittenByTheBug wrote on 5/13/2010, 10:35 PM
Thanks GlennChan and TheHappyFriar.

What shows in the Waveform-Luminance is not what I expected. Even after applying Broadcast Colors and set to Extremely Conservative-7.5 setup, the white does not come down to 100. I can use the Levels filter to pull the white down. Still wonder why the Broadcast Colors filter does not clip the highlight at 100.

Vectorscope, Histogram, and RGB Parade make sense though. Nothing illegal shown on them.

I misspoke when I said the Soft Contrast FX set the white to 108 and black to -8. They were there in the original clip - a small area of bright highlight (108) and a small area of deep shadow (-8).

This piece is for web only so I am glad to learn from TheHappyFriar that nothing is illegal in computer. The color correction actually looks good on my PC monitor. Nonetheless, I took this chance to read Glenn's article again and learned something from a new angle.