How to reserve a book — screen recording

How to tell whether you need 1.2.7

1. Write the description you would need for 1.2.5.
2. Read it aloud against the video, using only the existing gaps in the audio.
3. If you cannot finish a description before the next thing happens, the pauses are too short and you need an extended version.

Software demos, screen recordings, lab procedures and anything with dense on-screen text are the usual candidates. A talking-head interview almost never is.

The cheapest fix remains the script. If the narration says what the screen shows, the pauses never need to carry the load and no extended version is required.