Which component is NOT affected by the aperture setting?

In photography, the aperture setting plays a significant role in controlling various aspects of an image, but it does not directly influence the focal length of a lens. Focal length is a characteristic determined by the design of the lens itself, which defines the angle of view and magnification of the subject being photographed.

Aperture affects shutter speed, image exposure, and depth of field. A wider aperture (smaller f-number) allows more light to enter the camera, which can lead to a faster shutter speed being used for correct exposure, while also reducing depth of field, thus isolating the subject against a blurred background. Conversely, a narrower aperture (larger f-number) allows less light to enter, often resulting in a slower shutter speed and an increased depth of field, where more of the scene is in focus.

Since focal length is intrinsic to the lens and does not change with the aperture setting, this is why it is the correct answer in this context.