Flash Photography at High Iso

[Kolourl3lind]

Will flash help to git rid of grain at high iso like 6400 and above?

[jrhoffman75]

If the flash is powerful enough to light your scene and allow a lower ISO then "yes" grain would be reduced.

[NicCharlesPhoto]

I would just like to add that when you increase the ISO that much. You lose tonal quality and dynamic range, aka the colors produced won't be as vibrant and shadow recovery if necessary will be more grainy.