photography
Exposure: Aperture, ISO speed, and shutter speed are the three core controls that manipulate exposure.
Camera metering: The engine that assesses light and exposure.
Depth of field: An important characteristic that influences our perception of space.
Understanding exposure
Exposure triangle
Shutter speed: Controls the duration of the exposure
The shutter spped, or exposure time, refers to how long this light is permitted to enter the camera.
Range of Shutter Speeds
SHUTTER SPEED|TYPICAL EXAMPLE
—|—
1 to 30+ seconds|To take specialty night and low-light photos on a tripod
1/2 to 2 seconds|To add a silky look to flowing water landscape photos on a tripod for enhanced depth of field
1/30 to 1/2 second|To add motion blur to the background of moving-subject, carefully taken, handheld photos with stabilization
1/250 to 1/50 second|To take typical handheld photos without substantial zoom
1/500 to 1/250 second|To freeze everyday sports/action, in moving-subject, handheld photos with substantial zoom (telephoto lens)
1/8000 to 1/1000 second|To freeze extremely fast, up-close subject motion
Note that the range in shutter speeds spans a 100,000× ratio between the shortest exposure and longest exposure, enabling cameras with this capability to record a wide variety of subject motion.
Aperture: Controls the area through which light can enter your camera
A camera’s aperture setting controls the width of the opening that lets light into your camera lens.
We measure a camera’s aperture using an f-stop value, which can be counterintuitive because the area of the opening increases as the f-stop decreases. For example, when photographers say they’re “stopping down” or “opening up” their lens, they’re referring to increasing and decreasing the f-stop value, respectively
ISO speed: Controls the sensitivity of your camera’s sensor to a given amount of light
