Concentrics: double loop film for 16mm projector

I have a new double loop 16mm work, posted on Vimeo here:

The work is a double film loop for 16mm film projector, silent, indefinite duration. Two identical loops, ten seconds long, but one shorter than the other by one frame, run through the same projector. Every ten seconds the conjunction between the two loops changes by a frame, generating shifts in the moiré patterns generated by the superimpositions. It takes  forty minutes (240 frames x 240 repetitions) to exhaust all the permutations.