How the 1-series target market has shifted over time, according to Canon's release announcements:
1DIV: "virtually every category from photojournalism and sports through nature, wedding, portrait and fashion to commercial, industrial and law enforcement."
1DX: "such fields as sports photography, photojournalism and studio photography"
1DX2: "aimed at sports, news and wildlife"
1DX3: "Ideal for sports and wildlife"
R1: "in a wide range of fields including sports, news reporting and high-end video production"