Chris Nielsen wrote:... Do you also think my problem was exacerbated by high ISO?
Probably as a high ISO is most likely applying Gain which can = Noise. I'm not sure which DJI camera you have on your Drone but the Zenmuse x3, x4s and x5 cameras I think, come with the various DJI Inspire drones. The Zenmuse x3 is very basic with a 1 2/3" sensor, the x4 is 1" and the x5 is MFT so for the entry level Zenmuse x3, an ISO of 100-200 should be all you need filming in normal daylight.
I'm from a broadcast background where video camera sensitivities are measured in Gain, not ISO. If your camera has a Native ISO of say, 100 with Gain at Zero dB and it is fitted with a lens of about f/2.8, it will be fine in daylight so long as you have a real iris to adjust. Many basic DJI cameras with fixed wide angle lenses don't have a real iris so they rely on a combination of Shutter and ISO to control Exposure. You need to find out or estimate the native ISO of your camera when no Gain is applied, (eg 800) lock it there, then set your shutter speed to 180 degrees (eg: 1/50th @ 25fps, 100th at 50fps, etc) and maybe use a variable ND filter to keep it there.
As I mentioned earlier, even the basic DJI X3 camera can shoot clean, noise free outdoor Log UHD at 25fps, shutter locked to 1/50th, ND 16 applied and ISO set to Auto. IMO unrealistically high shutter speeds completely ruin 90% of all DJI/GoPro videos posted to the popular streaming services.