Why one frame per year lands
Ageing timelapses are ordinary now, and most of them fail the same way: they morph, so nothing feels like time passing, just a face melting. Locking one frame to one year gives the sequence a unit, and a unit is what makes a span feel measurable. Eighty small steps read as a life; a smooth blend reads as an effect.
Getting a clean run
Front-facing and close. Anything the model has to keep track of at the edge of frame — a background, a second person, a hand — is something it can lose hold of over eighty transitions, and a slip in the middle breaks the illusion of one continuous person. Even lighting helps for the same reason: hard shadow tends to drift across the face as the years move.