The HVX200 is a very noisy camera, even with a lot of light. The answer for me was “Neat Video” denoiser as a FCP plugin. There is also Red Giants Denoiser. Either of these plugins will remove all the grain from the image, use with caution tho, if you are too heavy handed the image can end up looking unnatural. But with practice you can get an amazing result. I can’t do without them now.