Certified Professional Photographer (CPP) Practice Exam

What effect does changing the f-stop have on the exposure?

1. It changes the color

2. It has no effect

3. It affects the motion blur

4. It influences the amount of light

The correct answer is: It influences the amount of light

Changing the f-stop, or aperture setting, directly influences the amount of light that enters the camera lens. Each f-stop represents a specific size of the lens opening; lowering the f-stop number increases the size of the aperture, allowing more light to hit the sensor. Conversely, increasing the f-stop number decreases the aperture size, letting in less light. This adjustment is crucial for achieving the desired exposure in a photograph. If too much light enters, the image can become overexposed, while insufficient light results in underexposure. The other options, while important factors in photography, do not directly pertain to the effect of changing the f-stop on exposure. Depth of field, for instance, is indeed affected by aperture settings, as a lower f-stop creates a shallower depth of field, but this is a separate consideration from exposure itself. Motion blur is related to shutter speed and how movement is captured, rather than the amount of light from the aperture. Color can be affected by various factors in photography, but it is not influenced by changing the f-stop directly. Thus, the option focusing on the influence of the amount of light accurately captures the primary impact of modifying the f-stop.