| Film Fanatic November 2002
Directing the Focus of an Audience: Part
One
Over the last couple of months we’ve
established that the camera lens is the "eye" of the audience. And a
cinematographer is able to manipulate an audience’s mood and perspective through this
"eye" by way of color and geometry.
There are, however, other techniques for directing the
human eye to a particular element in the frame. In addition to composing long shots,
medium shots, and close-ups, focus is the subtlest way of communicating or concealing
information within the context of a filmed frame. Look at the "shot" as a coarse
adjustment, while focus is a finer adjustment within the "shot."
Focus simply defined
When reflected light hits a glass lens it slows down and
bends. The distance of the object and the design of the lens dictate how much a ray of
light will bend. This bending ultimately causes rays of reflected light to reach the film
at different times. This time delay creates an image that is out of focus -- or not sharp.
When you focus a lens, it aligns rays of light so that they arrive at the same time and
therefore create a sharp image.
Focus, courtesy of man and machine
The human eye is an example of one type of lens. As
I’m sitting, writing, and wondering about the time, my eye focuses from my computer
monitor (one physical plane) to the clock standing six feet away (another physical plane).
By telling my eye to target the clock, I’m also asking it to focus on a different
plane (at a farther distance) and align the light rays, which are reflected off the clock
on that plane.
Here’s another example. Take both of your hands and
put them about six inches in front of your eyes. Both hands should be in focus. Now move
one hand out another six inches so that one hand is six inches away and the other is a
foot away from your face. Depending on which way you look, one hand will be clear (in
focus) while the other is fuzzy (out of focus). The six inches that separate your hands
constitute two different physical planes.
The human eye is a remarkable organ. Its ability to target
and focus light is incredibly quick and practically seamless. Sometimes it happens so fast
that the act of "seeing" seems almost involuntary. And despite advancements in
technology, there is no camera that can focus as seamlessly as the human eye. The
auto-focus mechanisms in expensive cameras come close, but an eye’s ability to
differentiate between two different physical planes is much more advanced. Even large,
expensive motion-picture cameras don’t rely on automatic focus. Film crews employ
people called "focus pullers" to adjust focus within a composed frame.
Keeping the man half in the dark
Often, focus pullers do not focus on what
the audience wants to see. They follow a director’s decision to misdirect the
audience by keeping objects out of focus, while at the same time naturally directing the
eye to what is in focus. Manipulating focus within a frame is a very powerful tool. We
depend on our gift of sight to keep us safe and aware of what’s around us. However,
being visually fuzzy as to what’s happening around you could be worse than having no
sight.
Think about it. At least in the dark, you would never know
what hit you. With fuzzy vision you’re aware of your fate, but handicapped and
powerless. Which is scarier?
Take the film Jaws -- specifically, the scene right
before Chief Brody (Roy Scheider) utters the famous line about needing a "bigger
boat." We see how subtle adjustments in focus and a frame’s composition can
foreshadow what’s coming up, and also lend a little bit of emotional imbalance to the
audience.
Chief Brody is reluctantly throwing chum off the side of
the Orca in hopes that it may attract the shark. Steven Spielberg frames this medium-tight
shot so that Brody is in sharp focus on the right side of the frame (one physical plane),
while the left side of the frame has the ocean slightly out of focus (another physical
plane). As Chief Brody throws chum in the water his hand moves into the out-of-focus part
of the frame. As an audience we accept the water and chum as secondary to Brody in the
foreground. But our anxiety builds because we know there is a shark in the water and Brody
isn’t paying attention. As a result, our eyes alternate between desperately trying to
see what Spielberg has chosen to keep out of focus and paying attention to what Brody is
stating. It’s only when the shark pops into frame that our fears are validated.
By leaving the water out of focus, Spielberg is
communicating two different messages: Listen to what Brody has to say, but be cautious
about what’s happening in the water.
But
Spielberg’s tricks with focus are hardly new. Spielberg protégé Tobe Hooper (Poltergeist)
uses focus in his vampire film, Salem's Lot, in a similar fashion. As vampire
hunters Ben Mears and Mark Petrie try to kill the mysterious Mr. Barlow, Mark is unaware
of the threat that moves behind him, just out of focus, in the root cellar. Like Brody and
the shark, objects in the background are kept out of focus until Mark finally turns
around.
Next month we’ll continue to "focus" our
discussion on depth of field and deep focus.
...Anthony Di Marco
anthony@hometheatersound.com |
