Using Zebra for green screen

[Matthew Romanis]

Connect the HVX to the Mac book (there may be a menu item you need to check in the HVX, I’m not sure), launch FCP, select the easy set up to suit the codec you are originating in (in your case DVC PRO 100 and the flavour you want), and open the log and capture window. You may need to select “Non Controllable device” from the device control tab.
Now click on the “Clip Settings” tab and select the “video scopes” button to see the scopes. They won’t show you real time, delayed by about 4-6 frames, but it is certainly good enough.
If the scopes window looks too small, close the log and capture window, make the canvas window as large as your screen can handle, then open the Log and capture window again making the same selections as before. The windows should now be much bigger.
Control click on the wave form and you can select between saturation and raw target data.

[Rick Pearl]

How accurate is using the scopes in FCP vs. using the $20,000 dedicated hardware that does the same thing?

[Matthew Romanis]

Of course there is a difference, especially in reading fine detail. Almost none of the features that make a good dedicated scope such a great tool are evident in the FCP scopes, they are merely a good guide. You do need to know how to read it and how to interpret what is being displayed.
The suggestion to use them follows on from your comments that you do not have access or budget for a good scope or quality monitor.
There are many ways to achieve what you need to do, I would strongly suggest some trial runs and test footage to key, there is only so much help that you can get from a forum, you need to trial some of these methods for yourself.