Poor lighting and video noise from small image sensors are the main reasons why Zoom video seems grainy. Under poor lighting, the camera will boost the signal from each pixel on the sensor to try and brighten the image. However, this also boosts the video noise, which appears as grain in the image.

How can I improve my Zoom video quality?

You can find this feature by logging into your Zoom account and clicking on “Settings.” Under “In Meeting (Advanced)” you can scroll down to find a feature called Enable Group HD Video which will increase Zoom's default standard definition to 720p HD video.

Why is video quality bad on Zoom?

If you're experiencing poor video quality (both on your end and incoming video streams), it may be the simple case that you're not using the right Zoom video features or settings. ... To adjust for low light, you can go to that same Video function within the Settings tab and enable the “Adjust for low light” feature.