Jacques-Henri LARTIGUE (1894-1896) & millions of amateurs since 1880 (the introduction of dry plates) and millions more since 1888 (the first Kodaks)

CONSTRAINT : subject is chosen according to the fastest shutter speed available, such that its velocity appears to be exactly annulled. This is achieved using the following formula : shutter speed = (focal length × subject speed) / circle of confusion (taken to be 0.036mm) × (subject distance in milimetres - focal length). Motion at 45° to the plane of the film can be doubled, and quadrupled at 90°. Trial and error has induced many to pan, and so to cheat by leaving the subject blurry, under the pretence that this imparts motion to the ϕ.

INVENTION/WORKS : ϕs of racing cars caught at close quarters and aeroplanes that cannot fly (Lartigue). The new technology offering fast exposures obliged subjects to jump when being ϕed.