Lighting

Key Light: the main and brightest light
Back Light: counteracts the key light and can be used to differentiate between the subject and its background.
Filler Light: usually reflectors are used to create this lighting and used to soften light and shadows
Under Lighting: comes from below the character and tends to have a distorting effect
Top Lighthing: light from above to create a glamorous mood
Back Lighting: used to create silhouettes when not many other lights are used


Casablanca (above) is well known for using the 'film noir' effect (typical of the 1940s/50s).  This effect is usually used in crime or dark and sinister films by creating a contrasting look using the key and back lights (low-key lighting).

Low-Key Lighting:
Created by using the key and back lights only.  The contrast creates a dark atmosphere and appearance (film noir).
High-Key Lighting:
More filler lights are used to create this type of lighting.  It makes the light seem natural and realistic.  Although there will still be shadows, they are not as pronounced or harsh compared to low-key lighting.