LIGHTING

CONTRAST RATIO

Sounds good, eh? And it's not that difficult to understand. It's the amount of light from the darkest part of a scene compared to the light from the whitest part. Your eye can see detail in very dark and very light areas - even if the light bit is a thousand times as bright as the dark bit. Cameras aren't nearly as good: photographic film can show detail in a picture with about eighty to one brightness ratio; video has trouble getting beyond forty to one.

Adjusting light to get a decent shot can mean problems. Here's a shot from inside a house showing a visitor with sky behind.

Okay if you're shooting a crime, perhaps, but if you want to see the visitor's face, not good enough. I'd go so far as to say yukky!

There are many ways around the problem:

	Bung lots of light on the visitor's face. Difficult to do in a confined space like a hallway.
	Wait for dusk, so the sky is much darker. Might work, but the right balance will only be there for a few minutes; no take two. And the lighting probably won't match the shots of the visitor walking up to the house.
	Shoot it from a slightly different angle. This wasn't possible here - but if there was a wall next to the doorway, that could have backed the shot. A small light on the face would probably still have been needed if the wall was white or pale.
	If the shot is all that important, can you shift the location to a flat where there's a lobby outside the front door?
	Don't actually shoot through the door! Do a cheat shot of the visitor well back from the house so there's plenty of light on the face. Cut to that from an exterior shot of the house owner opening the door and looking out.
	Probably easiest: Track back and zoom in so that there's a building or tree behind the subject, not sky:

THE ACTUAL LIGHTS

Lights come in all shapes and sizes, but you're really only concerned with two things; the power of the light and whether it's a hard or soft source. The power can vary from little fifty watt things up to several kilowatts, but most small crews use lights that use three hundred to six hundred watt bulbs.

Don't worry for the moment why you might need a hard or a soft source - I'll cover that later.

A hard light in its simplest form is a bare bulb. If you just stick a bulb near a face, though, you're wasting most of the light. So most hard source lamps use a reflector (like a torch) and/or a lens on the front to direct the light much more efficiently. In addition the light will probably be fitted with shutters or barn doors to give even more control. (You may want to light up a person, but not the hard white wall to the side, for instance).

You can make a hard light into a soft light by clipping translucent gel or tracing paper to the barndoors, or by bouncing the light off a reflecting surface of some kind. Expanded polystyrene is everywhere, light enough to tape to any surface and very cheap.

You can buy purpose made soft lamps; you've probably seen a photographer's umbrella lamp. It's a fancy variation on the expanded polystyrene theme. There are various lamps with a built-in translucent screen (or an add-on frame). They work on the same principle as sticking the white gel in front of the light, but they generally give a larger, therefore softer, light. In addition, there are flat lamps with banks of special fluorescent tubes. They give a cool, soft light, but they're a bit unusual outside the studio. For most purposes you can light almost anything with three or four simple reflector lamps.

NATURALNESS

Well, as I hinted in the bit about contrast ratio, using natural light often doesn't look very natural! You need to give nature a helping hand. Lighting setups vary enormously, but they all rely on the same basic principle - four point lighting.

Next - Four Point Lighting.