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Videography Basics
White Balance and Why It’s Important
White balance is important because it is how cameras determine the proper hue of
colors in a given environment. An object's color is determined by how it absorbs
and reflects light. This means that the apparent color of things is dependent on the
light hitting them. All light sources have a hue or color tint that varies. Anyone
who has suffered an eight hour day under the glare of bad fluorescent lighting can
attest to this! Things seem to gain a ghastly greenish hue under fluorescent lights.
It's a substantially different hue than the sunlight found outdoors on a cloudless
day. Even sunlight varies its hue depending on the time of day and cloud cover.
The hue of the ambient light (sometimes called “color temperature”) makes
objects that receive that light appear different. It can even impact how people feel.
In the movie “Joe vs. the Volcano”, Tom Hank's character claimed that fluorescent
light can “suck the life out of you”. While that may not be entirely true in a scien-
tific sense, we sometimes feel like it's not far off the mark.
The human eye actually adapts fairly well to ambient lighting changes and “cor-
rects” for them. When you are in a room that has strong green light in it, a white
piece of paper actually looks greenish but your brain corrects for this and lets you
“see” that paper as mostly white. The problem is that a person seeing an environ-
ment through the magic of your camera lens isn't actually there and their eyes
aren't getting all those subtle cues about the hue of the ambient lighting in the
environment.
This is why cameras have a clever function that lets them “learn” what hue the
light is in a scene and adjusts for it. This function is called Manual White Balance
and it works by being shown something in the ambient light that is assumed to be
white. This function tells the camera, “Ok, whatever this looks like to you, adjust
your color tuning to make it look white”. In actuality the “white” probably
appears somewhat greenish under fluorescent lighting or reddish under incan-
descent lighting. This process allows the camera to adjust to the environment's
ambient lighting. Once the white object is adjusted to appear white, the other col-
ors from red to blue to green will all appear proper under the current ambient
lighting.
Modern video cameras also have an Automatic White Balance function that
attempts to determine the proper hue adjustments based on what the camera sees
in the scene. As you can imagine, this can be a hit or miss proposition that
depends on the content of the scene. In the interests of career preservation, most
professional videographers religiously set the white balance on their cameras
manually. This prevents the camera from making a bad “automatic” assumption
during shooting and turning a fair-skinned person in front of a deep red curtain
into a slightly sunburned Smurf (don't laugh, it happens)!
If you want to get great looking video with color that's properly adjusted for the
current ambient lighting, spend a few moments setting the manual white balance
on your camera and verify it with DV Rack’s Sureshot component. In general it's
best to avoid ambient lighting transitions during a shot, if at all possible. In some