The blink cut
Eras change the way a person changes what they see: by blinking. The old picture leaves as its machine switched off, the lids hide the swap, and the new one arrives as its machine warmed up.

1970 to 1981 in twelve frames. The tube collapses, the dark holds, the bitmap draws in.
The problem
Ten pictures of one eye have to change into each other. A crossfade shows two faces at once. A slide turns the eye into a card. Both admit that these are images being swapped.
The move
The eye blinks, and the cut happens while it is shut.
- Lookfor 70 ms the eye glances the way you are travelling
- Closethe lids come down while the old era leaves in its own way
- Shutthe swap. Light, lens, page, sign and gaze all change at once, unseen
- Openthe new era arrives in its own way as the lids lift
- Readyits sign appears last
A fast sweep across several eras keeps the eye shut until the hand slows. Nothing flashes past.
Where the idea came from
Three rival concepts for the transition were written and three judges chose between them. All three picked the blink independently. It was the only one where the transition was something the subject does, not something done to it.