Zebra Settings?

[stanw]

What is the difference between the Zebra 80% and zebra 100%?

Thanks.

[Luis Caffesse]

The Zebra stripes are showing you the IRE levels of the image - (essentially brightness)

so 80% is showing you what is at 80% on the IRE scale - 100% is showing you what is at 100% of the scale.

Anything over 100% is going to clip and go pure white.

You can see the IRE levels of your footage on a waveform monitor (in your NLE software) to get a better idea of what this means.

[stanw]

1.) So essentially, if Zebra is set properly, there should not be any issues with having "illegal" colors that are not broadcast safe, that need to be manipulated using color correction tools in a program such as, Final Cut Pro?

2.) Why would you need to view it at 80% when anything over 100% is really the amount to be concerned with?

Thanks!!!!

[Luis Caffesse]

1) Not quite - while your luma levels will be legal, your saturation coudl still be above 'legal' limits. The zebras are only giving you feedback on the luma (or brightness). Your color (saturation) levels are another matter.

2) Because while you want to make sure nothing is cliped, you also need to keep an eye on your talent and/or subjects. You don't want to wind up with the talent's face at only 20% brightness in order to keep your highlights from clipping (for example).

[THoff]

The IRE level is separate from broadcast-safe colors -- it tells you whether highlights are clipping.

IRE levels below 100 are important for properly exposed skin tones (typically around 70% for caucasians, for instance) as well as green screen work (typically around 40%).

[stanw]

1.) Is there anyway to ensure that saturation does not go above the "legal" limit during a shoot, or is this just something that has to be done while editing?

2.) If I am shooting video with a caucasian, how do I ensure that the IRE is at 70%?

Thanks guys!!!

[Luis Caffesse]

The 70% number is a guideline - it all depends on the scene you're shooting and the skin tone of the talent involved.

As far as monitoring these values on set - you would have to run your signal to a wavefrom and vectorscope using something like DVRack, etc.

[THoff]

You could set the zebras to come on at 70% and adjust the iris or lighting so the zebras just come on for parts of the face.

Another way to do it is by using the MARKER function, which reports the IRE level for a small rectangular area of the scene -- put the MARKER on the face of the subject and you can see the IRE level next to it.

Speaking of DV Rack (now called Adobe OnLocation), it has both dark and light zebras. Light zebras are the ones most people are familiar with, they turn on when a given brightness level is exceeded. Dark zebras come on when the brightness level drops below a given level. DV Rack has both, and allows both to be active at the same time. Instead of one dark and one light zebra, you can also have two zebras of the same type at different brightness levels active.

[stanw]

"You could set the zebras to come on at 70% and adjust the iris or lighting so the zebras just come on for parts of the face."

Are you suggesting that if it is set to 70% and after making adjustments, I leave some of the zebras on parts of the face, that would be a sufficient indicator?

I will look into the MARKER function, I have not used it yet.

Does anyone know if there is an equivalent to OnLocation within the Final Cut Pro Suite?

Thanks!

[THoff]

Yes. You will never get uniform exposure for the entire face, and if you did, it would only be useful for a cosmetics commercial. If you set the zebra for 70% and it appears on prominent parts but not the whole face, you'll like have a properly lit face.

The closest thing to DV Rack/OnLocation on the Mac are DVMonitor and Scopebox.

[stanw]

Thanks so much for the help Luis Caffesse and THoff!!!!!!!!!!

[Luis Caffesse]

No problem.
Just don't post a video that's all over or underexposed next week.
:thumbsup: