Checking Luminanace Range in Final Cut Pro
If by surprise you are receiving either red or green lines througout your video in the canvas, you have probably pressed Control and Z by accident. When you see these zebra lines, Final Cut Pro is checking the luminance levels of your video, this is called Range Checking.
Along with these stripes you will also receive one of three symbols at the top of the current clip located in the Canvas Window. A checkmark in a green circle signifies that luminance levels for the current frame are safe and below 90 percent. There are usually no zebra lines present when this lone checkmark is present.

The next symbol is a checkmark in a green cirle with an arrow pointing upwards. This signifies that some of the luma levels are between 90 and 100 percent and you will see the suspect areas shrouded in green zebra stripes. This is also an acceptable level.
The next symbol is a yellow warning icon, which means your levels are over 100 percent. This icon is accompanied with red stripes over the problem areas.
Press Control Z to activate this function and press them again to deactivate it.


