Aperture is the adjustable opening inside a camera lens that determines how much light reaches the camera sensor. It is measured in f-stops (such as f/1.8, f/4, or f/11). A lower f-number means a wider opening that lets in more light, while a higher f-number means a smaller opening that reduces the amount of light. Aperture plays a major role in exposure, depth of field, and the overall look of your images.
How Does Aperture Affect Exposure?
Aperture directly controls the brightness of a photo. A wide aperture allows more light to hit the sensor, making images brighter—ideal for low-light situations. A narrow aperture limits light, resulting in darker images, which works well in bright conditions. Aperture works together with shutter speed and ISO as part of the exposure triangle to create a properly exposed photograph.
How Does Aperture Affect Depth of Field?
Depth of field refers to how much of the image appears sharp from front to back. A wide aperture creates a shallow depth of field, separating the subject from the background with a soft blur (bokeh). A narrow aperture produces a deep depth of field, keeping both foreground and background in focus—perfect for landscape and architectural photography.
When Should You Use Wide or Narrow Aperture?
Use a wide aperture for portraits, detail shots, and low-light scenes where subject isolation is important. Choose a narrow aperture for group photos, landscapes, and situations where you want maximum sharpness across the frame. Understanding when to adjust your aperture helps you control both the technical and creative aspects of your photography.
