Aperture, Iris and Exposure
People often get confused between iris, aperture, exposure and other related photographic terms.
Here are the differences in a nutshell:
- The iris is the part of the camera that has an adjustable opening to allow light to enter and fall upon the image plane (i.e. the sensor CCD, film, etc).
- The aperture is the size of the opening in the iris.
- Exposure is the amount of light falling upon the sensor.
Although the iris/aperture is the primary method of controlling exposure, there are a number of addition methods, including:
- Filters (e.g. neutral density filter)