I understand ND and how it works, but not understanding how to dial in the desired shutter speed on the Air 2S. Do you lock the shutter speed in Auto and let the drone adjust ISO, or do you go to Pro mode and take full control of the histogram? I thought I could let Auto do the initial settings so I could see what shutter speed my filter was producing, but the drone seems to adjust ISO dynamically to hold 1/100, and I don't seem to have control of shutter speed. Not what I expected. How is this done?