Certified Professional Photographer (CPP) Practice Exam 2025 - Free CPP Practice Questions and Study Guide

A larger lens opening, often referred to as a wide aperture, has a significant effect on the depth of field in photography. When the aperture is opened wider, the depth of field decreases, which means that the area in focus in an image becomes narrower. This results in the background appearing blurrier.

The correct understanding is that a larger lens opening allows for a shallower depth of field, causing the subject to stand out in focus while the background is blurred. This technique is often used in portrait photography to isolate the subject from the background, enhancing the visual appeal of the photograph.

The other choices do not accurately reflect the effect of a larger aperture: a sharper background would actually result from a smaller lens opening, while distortion and color saturation are not directly influenced by aperture size. Therefore, a larger lens opening leads to a blurrier background, which is a key concept in controlling depth of field in photography.