Aperture, often denoted as f-stop, controls the size of the lens diaphragm opening through which light passes to reach the camera sensor. A lower f-stop number (e.g., f/2.8) signifies a wider aperture, allowing more light into the camera and creating a shallower depth of field. A higher f-stop number (e.g., f/16) indicates a narrower aperture, reducing the amount of light and producing a greater depth of field, where more of the image is in focus. On Canon cameras, the f-stop is typically adjusted through a control dial, often located near the shutter button, while in aperture priority (Av) or manual (M) shooting modes. The specific dial and menu navigation may vary depending on the Canon camera model.
Mastering aperture adjustment is fundamental to photographic control. It influences both the brightness of an image and the extent of the area appearing sharply focused. The ability to manipulate aperture enables photographers to creatively manage depth of field, separating subjects from backgrounds for artistic effect or ensuring sharpness across an entire landscape. Historically, aperture control was purely mechanical, involving manual adjustment of the lens diaphragm. Modern Canon cameras offer electronic aperture control, allowing for precise adjustments and integration with other camera settings, such as shutter speed and ISO.
