What is the main function of the iris in a camera?

The main function of the iris in a camera is to regulate the amount of light entering the lens by controlling the aperture size. The iris acts like a diaphragm, expanding or contracting to either allow more light or restrict it, depending on the lighting conditions and the exposure settings chosen for the shot. This regulation is crucial for achieving proper exposure and depth of field in images.

The size of the aperture affects not only how much light hits the sensor but also influences aspects like depth of field, which determines how much of the scene appears in focus. A larger aperture allows more light to enter, which is beneficial in low-light situations or for creating a shallow depth of field, while a smaller aperture restricts the light, which can be useful in bright conditions to avoid overexposure.

This function is integral to achieving the desired photographic results, making the iris a critical component of camera operation. Other choices focus on different aspects of camera functionality that do not relate directly to the iris's purpose.