Exposure Triangle

What is Exposure?

In photography, exposure is the amount of light per unit area (the image plane illuminance times the exposure time) reaching a photographic film or electronic image sensor, as determined by shutter speed, lens aperture and scene luminance. (Wikipedia)

Aperture

1. What is it?

2. How is it measured?

3. Image

4. How does affect the image?

Shutter Speed

1. What is it?

2. How is it measured?

3. Image

4. How does affect the image?

ISO

1. What is it?

2. How is it measured?

3. Image

4. How does affect the image?

What is Equivalent Exposure?

An equivalent exposure is an alternative combination of settings (Aperture, Shutter Speed and ISO) that permits an equivalent amount of light in an image but allows a different compositional quality: frozen or blurred motion, small or large depth of field, etc.

The exposure triangle is a common way of associating the three variables that determine the exposure of a photograph: aperture, shutter speed, and ISO.