The way you change the aperture on your lens depends on whether you have a manual lens or a modern lens controlled by your camera.
Changing Aperture on a Manual Lens
On a manual lens, you change the aperture by rotating the aperture ring on the lens barrel. This ring is usually marked with a series of f-numbers (also called f-stops) such as f/2.8, f/4, f/5.6, f/8, and so on.
- Locate the Aperture Ring: Find the ring on your lens barrel labeled with f-numbers.
- Rotate the Ring: Turn the ring to the desired f-number. Remember that:
- A smaller f-number (e.g., f/1.4, f/2.8) means a larger aperture opening, letting in more light and creating a shallower depth of field.
- A larger f-number (e.g., f/16, f/22) means a smaller aperture opening, letting in less light and creating a greater depth of field.
Changing Aperture on a Modern Camera Lens
With modern lenses and cameras, the aperture is typically controlled electronically through the camera body.
- Set the Camera to Aperture Priority (Av or A) Mode: This mode allows you to select the aperture while the camera automatically adjusts the shutter speed to achieve proper exposure.
- Use the Camera's Control Dial: Usually, there's a dial or wheel on your camera that you can rotate to change the aperture setting. The exact location and function of this dial vary depending on the camera model, so consult your camera's manual.
- View the Aperture Setting: Look at the camera's display (LCD screen or viewfinder) to see the current aperture setting. As you rotate the control dial, the f-number will change, indicating the new aperture value.
Important Considerations:
- Understanding f-numbers: F-numbers represent the ratio of the lens's focal length to the diameter of the aperture opening. A lower f-number indicates a wider aperture and vice versa.
- Depth of Field: The aperture significantly affects the depth of field (the area of the image that appears acceptably sharp). Wider apertures (smaller f-numbers) result in shallow depth of field, ideal for isolating subjects. Narrower apertures (larger f-numbers) result in greater depth of field, suitable for landscapes.
- Exposure: The aperture is one of the three key elements (along with shutter speed and ISO) that determine the exposure of your photo. Adjusting the aperture affects the amount of light reaching the sensor.
