When an aperture is open wider, it lets in more or less light?

When the aperture is open wider, it lets in more light. The aperture is an adjustable opening in a camera lens that controls the amount of light reaching the camera sensor. A wider aperture, indicated by a smaller f-number (like f/2.8 as opposed to f/8), means that the diaphragm inside the lens has a larger opening. This larger opening allows more light to enter, which can help in low-light conditions and also affects the depth of field, providing a shallower focus that isolates the subject against a blurred background.

Thus, the ability to control the light entering the camera is crucial for achieving the desired exposure and creative effects in photography.