Certified Professional Photographer (CPP) Practice Exam

To solve for the exposure equivalent at F16 when given the exposure equivalents at F8 and F11, it is essential to understand the concept of f-stops and their relationship to exposure.

Each full stop change in aperture (either opening it up to a larger number or stopping it down to a smaller number) halves or doubles the amount of light hitting the sensor, respectively. In this case, moving from F8 to F11 represents a one-stop decrease in light, while moving from F11 to F16 represents another one-stop decrease.

Given that E = F8 @ 125, if we stop down to F11, we need to double the exposure time to maintain the same exposure level, which changes it from 1/125 seconds to 1/60 seconds. Now, moving from F11 to F16 means we are decreasing the light again by another stop, which would require doubling the exposure time again.

Starting from E = F11 @ 60, we double the exposure time to maintain equivalent exposure at F16. Doubling 60 seconds gives us 120 seconds total. However, since we're typically expressing times in fractions of a second in photography, this translates to a balanced exposure equivalent of 1/30 seconds (as