How to set the Sony a6400 video not to smear?

Use appropriate shutter speed, improve ISO and adjust exposure compensation.

1. Use an appropriate shutter speed: Setting the shutter speed to twice the reciprocal of the frame rate can effectively avoid smear.

2. Improve ISO: When shooting in low light, you can moderately improve the ISO value and increase the sensitivity of the camera to reduce the probability of blur and smear.

3. Adjust the exposure compensation: In strong light or high contrast environment, using the exposure compensation function can help you achieve a better exposure balance, reduce areas that are too dark or too bright, and reduce the appearance of smear.