Continuity errors
The mistakes that keep turning up
A continuity error is something in the world changing between shots when the story never said it should. Film has fought these for a hundred years with a person whose whole job is writing down where the glass was. Generated video gets the same errors for a different reason, and gets them a lot more often.
Here are the usual suspects, why each one happens, and how to check a clip without watching it frame by frame.
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Eight kinds, in rough order of how often
- Props
- The glass refills itself. The cigarette gets longer. The book is on the other side of the table.
- Somebody ate and drank through fifteen takes and nobody logged how much was left.
- Wardrobe
- A collar changes colour, a jacket buttons itself, a watch swaps wrists.
- Two shooting days, two dressers, one costume that was not photographed carefully enough.
- Hair and makeup
- The fringe is parted the other way. A cut on the cheek has healed by the reverse angle.
- Hours between the wide and the close-up, and hair does not sit still.
- Screen direction
- A car heading left is suddenly heading right. Two people talking both look the same way.
- The camera crossed the line between the shot and its reverse and nobody caught it in the edit.
- Light and weather
- Overcast in the wide, hard sun in the close-up. Wet road, dry road, wet road.
- The sun moved, or the second unit came back a week later.
- Where things stand
- Someone is by the window, then by the door, with no move in between. Furniture shifts.
- The set was reset by eye instead of from a photograph.
- Eyelines
- He is talking to somebody roughly a foot above her actual head.
- Coverage shot separately, with a mark in the wrong place.
- Time and season
- A single afternoon that starts in summer leaves and ends in bare branches.
- A long shoot, a long story, and a calendar nobody drew out.
Why they happen in the first place
Nothing is filmed in the order you watch it. The wide shot and the close-up of the same second can be two days apart, and in between, everything in the room has to go back exactly where it was. That is why the job of script supervisor exists, and things still get through.
Generated video has the same problem with the memory taken out. Each shot is made fresh, so there is no room to put back and nothing to put it back from. The jacket is not re-buttoned wrong. It comes back as a slightly different jacket, and the shot looks perfectly fine until you watch it next to the one before.
Compare with the first shot, not the last
Check each shot against the one before it and small drifts stack until the person at the end is not the person at the start. Check every shot against the first clear look and they do not.
What the check gives you back
Upload a clip and you get a score, a mark on the timeline at every break, the two frames that disagree with their timecodes, and a written note per problem you can copy straight into your next generation.
Common questions
- What is a continuity error?
- Something in the world of the film changes between shots when the story says it should not have. The glass is full, then it is half empty, then it is full again. The scene was shot over two days and the two days did not match.
- What is the most common continuity error?
- Props. Food and drink most of all. Somebody has to eat and drink through fifteen takes, and by the end nobody remembers how much was left at the start of the shot.
- Why do continuity errors happen at all?
- Shots are not filmed in the order you watch them. The wide shot and the close-up of the same moment can be hours or days apart, and everything in the room has to be put back exactly where it was. A script supervisor spends the whole day on this and things still get through.
- Are continuity errors different in AI video?
- Same categories, different cause and much higher rate. There is no room to put back, so nothing is remembered between generations. A jacket does not get re-buttoned wrong, it comes back as a slightly different jacket.
- How do you check a clip for continuity errors?
- Pick the first clear look at each person, room and prop, then hold every later shot up against that one instead of against the shot before it. That is what the check on this page does, and it gives you the timecode and both frames.
Where to go next
If the errors you keep hitting are about people, the character consistency page goes deeper on faces, clothes and what they carry. The analysis page explains how the check reads a clip, and published runs sit on the live benchmark.