Particulate Matter

Particulate Matter

Particulate matter in the air infl uences how objects appear
at different depths. What is this matter? Fundamentally, it

is water and other gas, dust, or visible particulate usually
known as pollution. Even in an ideal, pristine, pollutionfree
environment there is moisture in the air—even in the
driest desert, where there also might be heavier forms of
particulate like dust and sand. The amount of haze in the
air offers clues as to
. The distance to the horizon and of objects in relation
to it
. The basic type of climate; the aridness or heaviness of
the weather
. The time of year and the day’s conditions
. The air’s stagnancy (think Blade Runner)
. The sun’s location (when it’s not visible in shot)
The color of the particulate matter offers clues to how
much pollution is present and what it is, even how it feels:
dust, smog, dark smoke from a fi re, and so on.

Essentially, particulate matter in the air lowers the apparent
contrast of visible objects; secondarily, objects take on
the color of the atmosphere around them and become
slightly diffuse. This is a subtle yet omnipresent depth cue:
With any particulate matter in the air, objects lose contrast
further from camera; the apparent color can change quite
a bit, and detail is softened. As a compositor, you use this to
your advantage, not only to re-create reality, but to provide
dramatic information.