Flashback shots look the same as present-day shots, so viewers lose the timeline.
Example scene
Present day is the rainy-night store; the flashback is a sunny day three years ago when Lin Xia and her sister shared an ice lolly in the same shop. Two shots, 5 seconds, inserted at second 20.
Steps
Set visual rules used only for flashbacks: warm yellow grade, soft light, light grain; never use them in the present.
Give characters a visible time-gap change in the flashback, e.g. longer hair or a school uniform, in its own fixed description.
Reuse the present-day empty-set plate for the flashback and change only time of day, light and dressing, so viewers recognise the place.
Enter the flashback through a trigger shot: Lin Xia stares at the freezer, then cut to the freezer in the memory.
Use a 6–10 frame dissolve or white flash in and out of flashbacks, and use the same one throughout.
Support it with sound: pull the rain down during the flashback and bring it back to full level on return.
Prompts
Flashback first frame
The convenience store by day, same layout as [present-day set]: counter on the left, freezers on the right, glass door centred, bright sun outside. 17-year-old Lin Xia: ponytail, blue-and-white school uniform; beside her, her 22-year-old sister: shoulder-length curls, beige knit cardigan. They stand at the freezer sharing an ice lolly, laughing. Warm yellow grade, soft backlight, light film grain, medium shot, vertical 9:16.
Flashback video
The sister snaps the ice lolly in half and hands one piece to Lin Xia, who takes it and laughs. Slow, small movements, locked-off camera. Keep the warm grade and soft light; keep both characters' looks, clothes and the store layout unchanged; no new people.
Negative
cool palette, night, rain, similar faces, swapped clothing, extra people, text
✕ Failed take
The flashback used the present-day cool grade and adult Lin Xia's look, hard-cut in: viewers thought the sister had suddenly appeared in the store that night and read it as a ghost story.
✓ Passing take
The first frame of the flashback reads as the past. Pass criteria: at least two of grade, light and character styling clearly differ from the present; the set layout is recognisably the same; entry and exit are consistent throughout; with sound off it doesn't need a “three years ago” caption.
Before/after clips are in production. Follow the steps and prompts to reproduce the result.