Apple Video System - Manual (Page 71)

The capture controls appear.
3 Wait until you see the image you want to capture.
The Controls window can remain open without affecting
what happens in the video window.
m To freeze the video image at the current frame, click Freeze.
The video freezes, and you can decide if you want to save
the current frame.
To unfreeze the video, click Freeze again.
m To save the current video frame on a disk, click Save.
If the video isn’t already frozen, it freezes at the current
frame until you complete the Save operation.
A dialog box appears so you can specify where to save the
image. When you click Save, the image is saved as a PICT file
under the name that you supply. (A PICT file can be opened
by most graphics programs.)
65 Capturing Video Images