Certified Professional Photographer (CPP) Practice Exam

When hand-holding a camera, the shutter speed should be equal to or faster than the:

1. ISO rating

2. Aperture size

3. Focal length of the lens

4. Sensor size

The correct answer is: Focal length of the lens

When hand-holding a camera, the appropriate shutter speed should be equal to or faster than the focal length of the lens being used. This relationship helps to minimize motion blur that can occur due to camera shake when taking a photograph. For instance, if you're using a 50mm lens, the shutter speed should be at least 1/50 of a second—or faster—to achieve a stable image. This principle is rooted in the physics of photography, where the longer the focal length, the more susceptible the image is to motion blur from even slight movements. Therefore, maintaining this ratio allows for clearer images without requiring the stabilization that tripods or other supports provide. While factors such as ISO rating, aperture size, and sensor size are essential for exposure and image quality, they do not directly influence the necessary shutter speed for handheld shooting. ISO determines the sensitivity of the sensor to light, aperture controls the amount of light entering the camera and depth of field, and sensor size can affect depth of field and noise levels. However, when considering the prevention of camera shake, the focal length of the lens is the critical metric.