Certified Professional Photographer (CPP) Practice Exam

What is the impact of using a larger f-stop on the depth of field?

1. It increases the depth of field

2. It decreases the depth of field

3. It has no impact

4. It shifts focus to the background

The correct answer is: It increases the depth of field

Using a larger f-stop, or a smaller aperture (indicated by a higher f-number), significantly increases the depth of field in your photographs. When the aperture is set to a larger f-stop, such as f/8 or f/16, more of the scene from the foreground to the background comes into focus. This is particularly beneficial when photographing landscapes or group shots where you want both near and far subjects to be clearly defined. The reason this happens is due to the physics of light and how it interacts with the lens. A smaller opening (larger f-stop value) reduces the amount of light entering the camera, which allows for a greater area in focus because it minimizes the effect of lens aberrations and sharpens the focus across the scene. In contrast, a wider aperture (smaller f-stop value) has a shallower depth of field, making it easier to isolate subjects from the background but causing less of the image to be in focus. Thus, using a larger f-stop is a deliberate choice for photographers aiming for extensive clarity throughout their images.