Certified Professional Photographer Practice Exam 2025 – All-in-One Guide to Achieve Your CPP Success!

The Sunny 16 rule provides a guideline for achieving the correct exposure in various lighting conditions. On a heavily overcast day, this rule suggests adjusting exposure settings from the sunny baseline. In bright sunlight, the rule indicates that at ISO 100, the correct exposure would be f/16 at 1/100 seconds. However, when the sky is overcast, the light is softer and less intense, leading to the recommendation of adjusting your aperture to give a wider opening.

Choosing f/5.6 at 1/ISO (for instance, at ISO 100) reflects this adjustment for overcast conditions. This setting allows more light to enter the camera compared to the sunny setup and takes into account the reduction in available light due to cloud cover. Thus, it provides a balanced exposure for the softer light conditions found on such days. This practical adjustment helps photographers effectively capture images without underexposure, making it the most suitable choice among the options.