Which aperture number indicates the largest opening and most light in photography?

In photography, the aperture is the opening in the lens that allows light to pass through to the camera sensor. The aperture size is represented by f-numbers, also known as f-stops. A lower f-number indicates a larger aperture opening, allowing more light to enter the camera. In the provided choices, f/2.8 is the smallest f-number, signifying the largest opening among the options listed. This enables the most light to reach the sensor, which is particularly beneficial in low-light conditions or when a shallow depth of field is desired to create a blurred background effect.

In contrast, f/22, f/16, and f/8 represent progressively smaller openings, allowing less light to enter. This is suitable for situations requiring greater depth of field, but they won't yield the same amount of light as the f/2.8 setting. Thus, f/2.8 truly stands out as the aperture that provides the largest opening and maximizes light intake.