Movies for TV - Early Television Foundation

LIGHTING 757
tion equally well with panchromatic film. The main objection to
cold lights in studios for other than fill lights is the fact that the
light source is so large that it is impossible to design
an efficient
optical system to direct the light emission.
Gas discharge tubes such as the mercury-arc light may help
to overcome this trouble. The Western Union Zirconium arc light,
which is very small and burns zirconium electrodes, is capable of
very high light emission and is almost heatless and fumeless. Its
small size and convenience should make it a natural for small and
baby spots.
When photographing sets containing light fittings, i.e., read-
ing lamps or overhead fixtures, etc., it is a problem to make them
register on the film if the lens is stopped down and a large amount
of other lighting is used, or if it is necessary to have a shot where
the light from one of these fittings illuminates the subject. In cases
like this, it is a simple matter to replace the ordinary light bulb
with a photoflood bulb. This is the bulb used by amateur photog-
need for indoor shots without the
raphers to provide the light they
expense of professional lighting equipment. As a matter of fact,
it is possible to use this type of bulb for many incidental shots es-
pecially if the film is being made for an insert and it is a very short
scene which has no difficult lighting requirements. The photoflood
bulb is similar to the normal type in appearance and screws into
the standard light socket. This means that it can go straight into
any fixture that is handy. The high light output is obtained by
overrunning the filament so that the life is quite short; it varies
according to the length of use, but a minimum of two hours is
almost always obtained. Because of this feature, it is a good idea
to use the ordinary bulb in the fixture when setting up the shot
and to replace it with a photoflood just before shooting. The lights
can remain extinguished until the time of filming. It is good practice
to maintain a record of the number of hours each bulb burns
to avoid the nuisance of having one burn out in the middle of a
shot. They are quite cheap to purchase and since they fit into any
type of holder with a standard screw base, of course the user
can make his own to suit himself.