Certified Professional Photographer (CPP) Practice Exam

What does setting a higher ISO do to the data captured by digital sensors?

1. Reduces the amount of noise

2. Amplifies the data

3. Brightens all exposures

4. Filters out unwanted pixels

The correct answer is: Amplifies the data

Setting a higher ISO amplifies the data captured by digital sensors, which essentially increases the sensor's sensitivity to light. This adjustment allows for better performance in low-light conditions and helps achieve correct exposures without the need to open the aperture wider or slow down the shutter speed. As the ISO value increases, the sensor amplifies the electrical signal it generates when capturing light. This amplification is necessary to produce a sufficiently bright image in environments with limited available light. However, it's important to note that increasing the ISO can also lead to increased noise in the image. Noise can manifest as graininess or irregular pixels, particularly in the darker areas of a photograph, which is why many photographers must balance the ISO setting with other exposure factors. The other options, while relevant to photography concepts, do not accurately describe the primary effect of increasing ISO. For instance, higher ISO does not inherently reduce noise; rather, it may increase it if pushed too high. Similarly, while a higher ISO allows for brighter exposures in low light, it does not uniformly brighten all exposures equally—exposure still depends on other settings like aperture and shutter speed. Lastly, increasing the ISO does not filter out unwanted pixels; that relates more to post-processing techniques or specific camera settings related to pixel management