Royal Academy shows usually have stilted narratives. That's not what they're good for. In this one, Degas appeared to have become a painter in his late 30s, painting exclusively dancers. He evokes them beautifully, carefully, intelligently, limbs and strength and motion deliminated in pastels and oils and charcoal.
But that's the framework for the show's central argument: the ongoing, changing relationship between Degas and the nineteenth-century development of photography and moving pictures, from stop-motion to the earliest films of the 1890s. "The Little Fourteenth-Year-Old Dancer" sculpture is shown as the culmination of numerous sketches in which the artist moved around his model in the same way that cameras moved around still subjects at the time. Muybridge's stop-motion photography influenced Degas and his exploration of movement. There are glorious sculptures - by people who are not Degas - of birds in flight, the moments of their motion melding together in the same way some stop-motion photography ends.
Fittingly, the show ends in the seconds of documentary recorded of Degas himself. He had turned down the documentary maker, not interested in being filmed for a piece on older artists. So the filmmaker laid in wait one day on the sidewalk, and captured him, for perhaps ten seconds, walking down the street, half-blind and unaware of the camera.