The campaign is designed to highlight how unreliable people’s memories can be in high-pressure situations by showing the wide discrepancy in the perceptions of witnesses and the reality of the situation.
Creative is shot from the perspective of the cameras worn by two officers, who arrive at the scene of a fight.
Audio of those giving an account of the incident varies significantly from the images captured by the cameras.
The film ends with a "body worn camera, an independent witness" strapline as it seeks to reassure the public that the cameras are designed to make policing more transparent and accountable.
The ad was created by Abbott Mead Vickers BBDO and the copywriter and art director Esrael Alem and Filmawi Efrem respectively. Ben Dawkins directed the film, which was produced by The Sweet Shop. Media was handled by MediaCom.
Metropolitan Police Service superintendent Adrian Hutchinson said: "With Body Worn Video we are launching what is thought to be the largest rollout of cameras anywhere in the world.
"It will support the public and our officers in many challenging incidents, giving us a valuable additional tool. Video can capture events in a way that can’t be represented on paper and in this film we hope to convey both the strength of the technology itself and the benefits it brings."