Noise in event photography can be caused by high ISO settings, long exposure times, poor lighting conditions, or a combination of these factors.

The most effective way to reduce noise in event photography is to use a lower ISO setting. This will reduce the amount of amplification applied to the signal, resulting in less noise.

Using a lower ISO setting will require a slower shutter speed, a narrower aperture, or both. This can lead to increased motion blur, reduced depth of field, or both.

Using a tripod, monopod, or image stabilization can help to avoid motion blur when using a lower ISO setting.

Using a wider aperture will increase the depth of field, while using a narrower aperture will decrease the depth of field.

Using a noise reduction filter can help to reduce noise in post-processing.

Using a noise reduction filter can lead to reduced sharpness, increased blur, and loss of detail.

Using a light touch, using a selective noise reduction filter, and using a noise reduction filter that preserves detail can all help to minimize the drawbacks of using a noise reduction filter.

Using a camera with a larger sensor, a camera with a better noise performance, and a lens with a wider aperture can all help to reduce noise in event photography.

The best way to learn how to reduce noise in event photography is to read articles and tutorials, watch videos and tutorials, and practice, practice, practice.