Smart crop
Also known as: content aware crop, intelligent cropping
Choosing where to cut a frame down so the important part survives, rather than taking the middle and hoping for the best.
Updated
What it means
Smart crop decides the position of a smaller frame inside a larger one. Reshaping wide footage for a taller format throws away most of the width, and which part goes is the entire question.
A centre crop is the naive answer and it fails whenever the subject is not central. Smart crop instead places the window where the content is, which is what Saliency detection is used to establish.
It is a per shot decision rather than a per clip one. The right position for a landscape wide is not the right position for the rider that enters it ten seconds later.
How it works in practice
The usual chain finds the subject, measures where attention falls, and places the window to contain both with a margin. Shooting wider than the delivery format is what makes any of that possible.
For a still frame it is a single choice. For moving footage the window has to follow, which is where it becomes Auto-reframe and depends on tracking holding the subject reliably.
Checking the extremes of a shot is worth more than checking the middle, because the frames where the subject nearly leaves are where a crop either works or visibly fails.
What to watch out for
Cropping discards resolution, and there is no way around it. A tall window cut from a wide 4K video frame delivers far fewer pixels than the original, which shows on a large screen.
Composition is also lost rather than preserved. A deliberate Rule of thirds placement becomes centred, and the balance the shot was built on disappears without anything looking obviously broken.
Horizons suffer in a particular way. A level horizon in a wide frame can meet the new edges awkwardly, and the correction is a rotation nobody asked for.
How RawClip handles it
Highlights are delivered in the shape they were filmed in, because cropping throws away both resolution and the framing decisions made while shooting. Reshaping for one platform is a deliberate step, better taken knowingly on a finished cut than applied automatically to every clip that happens to be wider than its destination.