Someone trimmed the sprocket holes from the left side.
He read from a computer printout with sprocket holes.
The image was photographed six sprocket holes high, rather than the usual four used in other 35 mm processes.
Later, machines that counted the sprocket holes were used.
"Walt lived every sprocket hole of this film," one animator said.
The camera itself punched a sprocket hole on each side of the frame as the film was exposed at 30 frames per second.
It has 24mm of usable film width once the space for the sprocket holes is subtracted.
A strip of film has small square holes along each side called sprocket holes.
Later optical readers used the sprocket holes to generate timing pulses.
That was when the studios would buy anything with sprocket holes that they could call a children's film.