Exposing Yourself to Exposures
Exposures control the amount of light entering the iris (also called the
aperture) of the camera lens, which reacts to the light and opens and closes
to allow more or less light into the camera. The human eye iris works
similarly, but the response is automatic. The film camera’s eye needs human
assistance to adjust the settings for focus, exposures, and so on. Most digital
camcorders have advanced circuitry and do a lot of this for you (when set
on automatic).
When you look outside on a bright day, the iris of your eye shrinks to a
smaller circle because the eye has plenty of light to see. The iris of the camera
works the same way; concentrated light is directed through the tiny aperture
of the camera causing objects to appear in sharp focus (this is also why
people who don’t have 20/20 vision see better during daylight hours than at
night). Have you ever noticed that when you turn off the lights in a room, your
eyes take a moment to adjust? That’s because your brain is telling your iris
that it needs to open wider to compensate for the lack of light. The iris of the
camera works the same way and has to be opened up wider to allow for more
light to enter the lens to be able to expose an image with enough light.Taking your color temperature
Different types of light radiate different color intensities, called color temperatures, which affect how the camera records the light. The color temperature
of the lighting affects the final colors in your film. Color temperature is determined by the intensity of light that radiates from your movie lights; don’t
confuse it with thermal temperature that measures hot and cold.
When you’re imagining how color temperature works, think of a blacksmith
heating up and shaping a horseshoe in a forge. As the black mass heats up, it
turns different colors. This is how color temperature works.
Our eyes adjust to the colors of light, something the camera can’t do without
some assistance. That’s why gels, white balance, and filters (see Chapter 10)
are used to get the film or video camera to see what the human eye sees. The
camera has a mechanical eye (with film cameras) or an electronic eye (with
digital cameras) that has to be programmed so that lighting will look natural
to what the human eye sees. Many camcorders do emulate the human eye
when you set them on automatic.
Every color has a temperature that’s measured in Kelvins (named after Lord
Kelvin, who discovered the system). Kelvin is a rate of measurement in
degrees, similar to Fahrenheit and Celsius, and it’s usually shortened to °K.
Warmer colors like red and amber have lower Kelvin ratings. For example,
sunlight is yellow, orange, and red — a lower Kelvin rating than the blue
Kelvin rating of the moonlight. Film is a sensitive material that lets light burn
its color into it. The higher the temperature in °K, the cooler the color. In
other words, the hotter the temperature, the bluer the hue; the lower the temperature, the warmer the hue (reds, oranges, yellows)