Lighting is used in many configurations to fit various purposes. Its intensity depend on many factors such as putting emphasis on an actor outfit or to creating a moving shadow to indicate another person is in the room. Dimmed Lighting may be used for an intimate scene or giving the impression of a confined room while bright light may indicate the opposite. In any case, the Director of Photography will set up the scene with the appropriate lighting to achieve the desired outcome. Professional light gear come in many sizes and is often very expensive, not to mention thirsty on energy. Is there a more cost-effective way to get great lighting instead of going with expensive professional gear? In fact there are many "tricks" that can be used to achieve great lighting on a budget.
One way is to use series of PAR38 light bulbs. PAR is for Parabolic Aluminized Reflector, which are great for directional lighting. The power recommended per bulb is 150 watts but if lighting a small room such as a prison cell, a lower wattage can do the trick. These bulbs are available in any hardware store, Tungsten seems to work best for cinematography, but also people also use fluorescent or LED. The average price per bulb is around $20.00. If you need 10 of them, it will provide 1,500 watts of lighting with a highly flexible way to place them and direct the light as needed, avoiding cumbersome professional light projectors.
Mountings are equally available and are inexpensive. For around $30.00 per bracket, you can set the light on any surface with all possible angles. You just need extension power cords with multiple sockets that can be easily hidden on the set of your film.
10 bulbs at $20 + 10 brackets at $30 + $30 of electric extension cords with multiple sockets will provide a reusable lighting set for around $530.00.
The most important part is the flexibility it provides, flooding lights with most bulbs in the same direction or spotlights as needed. Some brackets will also provide the capability of reducing intensity and adding filters.