Certified Professional Photographer (CPP) Practice Exam

Which is the highest whole ISO number listed for common photography?

1. 800

2. 3200

3. 6400

4. 1600

The correct answer is: 6400

In photography, ISO measures the sensitivity of the camera's sensor to light. A higher ISO number indicates greater sensitivity, allowing for better performance in low light conditions, but it can also introduce more noise into the image. Among the options provided, the highest whole ISO number is 6400. This is significant because it represents a level of sensitivity that is suitable for shooting in very low light situations, where other settings may struggle to produce a properly exposed image. At ISO 6400, photographers can capture images without the need for additional lighting, which is especially useful in environments such as concerts or events where flash photography might be restricted. While ISO 800, 1600, and 3200 are also commonly used settings in photography for varying light conditions, they do not reach the sensitivity level offered by ISO 6400. Understanding the advantages and limitations of different ISO settings is crucial for photographers to make informed choices based on their shooting environment and desired outcomes.