Page "History of film" Paragraph 86

With the increased production required by the nickelodeon boom, extra artificial lighting was used more and more in the film studios to supplement diffuse sunlight, and so increase the hours that film could be shot during the day.

The main sources used were modified arc lights made for street lighting.

These were either hung on battens suspended forward of the actors from the roof, or mounted in groups on floorstands.

The addition of a metal reflector round the arc source directed a very broad sweep of light in the desired direction.

Large mercury vapour tube lights ( Cooper-Hewitts ) were also used in racks placed in the same way.

Arc lights had been used to produce special lighting effects in films like the light from a lamp or firelight before 1906, but this now became more common.