Eight seconds — that's how long a cowboy needs to stay on a bucking bronco to qualify for a rodeo score. For photographers, that's barely enough time to take just a few blurry, often unusable pictures.

"In the past, these images would have been made by pre-focusing and praying for the best," said Kenneth Jarecke, who made his name shooting photos during the Gulf War.

His praying days are over. Jarecke is an early adopter of a new breed of mirrorless cameras made by Sony Corp. that excel at capturing crisp shots of fast-moving objects. Unlike digital single-lens reflex (DSLR) cameras, his Sony Alpha a7R III ditches the mirror-and-prism system that shows what's coming through the lens. The Alpha's mirrorless design lets image sensors grab light faster and stay in focus using sophisticated software. It's potentially a tectonic shift that gives Sony a chance to break the pro-photography duopoly Canon Inc. and Nikon Corp. have enjoyed since the days of 35mm film.