Shutter Speed
The time the shutter is open to expose light into the sensor.
Typically measured in fractions of a second.
Slow shutter speeds means more light into the sensor
Examples of shutter speeds: 1/15 (1/15th of a second), 1/30, 1/60, 1/125.
Aperture
How big the hole of the lens is open.
The larger the hole, the more light.
Aperture also controls the depth of field.
Small aperture = large depth of field
Large aperture = Small depth of field
Typically expressed in “f” numbers (for “focal ratio”)
Examples of f-numbers are: f/1.4, f/2.0, f/2.8, f/4.0, f/5.6
ISO
Artificially brighten your photos
Measured in numbers (no kidding 😉 )
Low number -> dark image
Higher numbers -> brighter image.
Con: as the ISO rises, so does the noise in your images.
Examples of ISO: 100, 200, 400, 800, 1600.