ISO (International Organization for Standardization) is a measure of the sensitivity of the camera sensor to light. A higher ISO allows the camera sensor to capture more light in low-light conditions, but also introduces more digital noise into the image.
In terms of video recording, the ISO setting directly impacts the quality of the video by determining how bright or dark the footage will appear. A higher ISO setting can help to brighten up a dark scene, but it also comes at the cost of introducing more noise and reducing the overall image quality. On the other hand, a lower ISO setting will result in cleaner footage with less noise, but may require more lighting to achieve a properly exposed image.
Ultimately, the ISO setting should be adjusted based on the lighting conditions of the scene to strike a balance between brightness and image quality. It is important to consider the trade-off between noise and image quality when choosing the ISO setting for video recording.