Explain how increasing ISO affects both light sensitivity and image quality.

ISO, which stands for International Standards Organization, is a setting on your camera that controls the sensitivity of your camera's sensor to light. Here's how increasing ISO affects both light sensitivity and image quality:

1. Light Sensitivity: ISO is one of the three factors that determine your camera's exposure (the other two being shutter speed and aperture). A higher ISO setting increases the sensitivity of your camera's sensor to light. This means that it requires less light to create a properly exposed image. This is particularly useful in low-light situations where you can't or don't want to use a flash, such as indoor events or concerts.

2. Image Quality: While increasing your ISO does allow you to shoot in lower light, it comes at a cost. Higher ISO settings can result in an increase in what's known as "digital noise" or "image noise". This noise appears as random specks of color that distort the image, similar to grain in film photography. The higher the ISO, the more noise you'll see in your image. This can reduce the overall quality of the image, making it look grainy or "muddy".

In conclusion, while increasing ISO can help you capture images in low-light situations, it can also degrade the quality of your images. Therefore, it's always a good idea to use the lowest ISO setting that you can get away with for the lighting conditions you're shooting in.