Which camera setting primarily controls depth of field and the size of the lens opening?

• A. Shutter Speed
• B. ISO
• C. Aperture
• D. White Balance

Answer: (C)

Aperture is the setting that controls depth of field and the size of the lens opening. When you open the aperture wide (a small f-number), more light enters the camera and the depth of field becomes shallower, so the subject remains sharp while the background and foreground blur. When you stop down the aperture (a larger f-number), less light enters and more of the scene stays in focus, increasing the depth of field. This happens because the aperture physically changes how much of the scene is accepted by the lens. The other options don’t control depth of field: shutter speed affects how long the sensor collects light (influencing motion blur), ISO changes sensor sensitivity and noise, and white balance adjusts color temperature.