Certified Professional Photographer (CPP) Practice Exam

What is a recommended way to reduce chromatic aberration?

1. Use larger lens openings

2. Use lower quality lenses

3. Use smaller lens openings

4. Use an image stabilization technique

The correct answer is: Use smaller lens openings

Using smaller lens openings is an effective way to reduce chromatic aberration, which occurs due to the lens's inability to focus all colors of light to the same convergence point. When the aperture is reduced, more light rays are directed towards the central part of the lens that typically has better optical properties, thus minimizing the dispersion of color and improving image sharpness. A smaller aperture increases the depth of field, which can be beneficial in achieving cleaner images where color fringing is less noticeable at the focused plane. This technique works particularly well when shooting in situations that require greater clarity and detail, as it helps mitigate the effects of lens imperfections. In contrast, larger lens openings can exacerbate chromatic aberration, as they allow more light rays from the edges of the lens to enter, which can lead to greater color fringing. Using lower-quality lenses would likely increase the occurrence of aberrations rather than reduce them. Image stabilization techniques generally help with motion blur but do not address chromatic aberration directly.