Show light for bovle film more mere daylight Is very rarely rolled upon wholly for the production ol of moving pictures for bright artificial illumination la Is necessary evon even on bright days tor for sunlight cannot be do upon tho the overshadowing of the sun tor for evon even a single moment would a strip 0 of film and necessitate re taking the action at bno time lime tho the are arc lamp was considered the most suitable form of studio lighting but today it has been almoas entirely supplanted b h the coope mercury vapor lamp As a rule it la Is assumed that tor for proper lighting there should be a current expenditure 0 10 0 watts in the mercury vapor lamps to each square toot foot of floor space stages lighted under these conditions having a floor illumination averl averaging gln g about 1 toot foot candles |