A common assumption going into a first shoot is that a 30-second video needs roughly 30 seconds of footage, maybe a bit more. In practice, a well-edited 30 seconds is usually built from several minutes of raw coverage, sometimes considerably more depending on the shot list. The gap between "enough footage to fill 30 seconds" and "enough footage to actually edit a good 30 seconds" is where most under-planned shoots fall short.
Why the ratio is so lopsided
Every cut in a finished edit needs options either side of it, an alternate angle, a slightly different take, room to trim the start or end of a clip so it lands on the right beat. None of that exists if the shoot only captured exactly what appears in the final cut. Multiply that by every shot in a 30-second edit and the raw footage requirement adds up fast, even though the final result looks simple and short.
Plan the shot list around variety, not duration
The most useful thing a client can bring to a shoot isn't a target runtime, it's a sense of the different angles and moments that need covering: a wide establishing shot, a closer detail shot, a moving shot, a static one. A shoot built around genuine variety in coverage gives an edit real options to work with. A shoot built around "just get 30 seconds of something" usually produces footage that's technically long enough but has nowhere near enough range to cut into something that holds attention.
Vertical and horizontal need separate coverage
If the same shoot needs to produce both a horizontal cut for web and a vertical cut for social, that's not the same footage reframed, it's effectively two separate shot lists shot in parallel, since a composition that works filled edge to edge horizontally rarely works cropped into a 9:16 frame. Planning for both formats before the shoot, not after, is what actually saves a reshoot.