In shots with bright sun and shadows, it’s difficult, if not impossible to compose a shot without using some sort of ND filter. To properly expose the bright sunny conditions in the shot you composed, the shutter speed is running at 1/1600, which is too fast for the sensor to also capture the details in the shadows, resulting in grain. In this shot, an ND 32 or 64 would have allowed the shutter speed to be decreased to 1/60ish for example, which would also allow more of the detail from the area in shadow to be captured by the sensor, resulting in less grainy footage.
Edit: Adding the below footage.
Here is an example of how shutter speed in high contrast situations can effect noise levels. I am still learning how to compose with my
MA, and I should have used a ND32 or ND64, instead of the ND16 I did use, but you get the idea.