I am assuming that the aperture, ISO and shutter speed that is used for the imagery captured during the mission is stored from the auto exposure variables (aperture, ISO and shutter speed) from the very first image - whilst the drone is still on the ground. An issue with this is that if the launch of the drone is in the shade. I experienced this yesterday when I launched a drone from between two beach houses and we were in-fact in the shade. This caused all of my imagery to be over exposed in the first half of my flight. I had to land the drone to fly part two of the mission and when I launched from an area directly in the sun and the exposure was perfect. I would suggest the exposure preset be created when the drone is about to take the very first photo in the mission, or use the exposure information from that very first photo captured during the mission.
Thanks!