How does a small f stop affect the amount of light that enters the lens?

A small f-stop number corresponds to a larger aperture opening in the lens, which significantly increases the amount of light that can enter. This is due to the way f-stops are defined; a smaller f-stop number (like f/2.8) means that the lens aperture is wider, allowing more light to hit the sensor or film. This increased light intake is beneficial in low-light situations and also impacts aspects like depth of field, enabling a blurrier background while keeping the subject in focus. The greater light entry facilitated by a small f-stop enhances exposure and increases the chances of achieving a correctly lit image.

In contrast, larger f-stop numbers (like f/16) correspond to smaller apertures, which allow less light to enter the lens. Thus, understanding the relationship between f-stop numbers and light entry is crucial for effective exposure control in photography.