Watched my neighbor's astro photos go from mush to sharp after he stopped shooting over his AC unit
My neighbor Dave shoots from his driveway in Mesa and his star photos always looked soft and wobbly. Last month he moved his rig about 30 feet to the side of his house, away from the AC exhaust, and the difference in a single night was nuts. Turns out the heat pouring off that unit was cooking his shots the entire time, and he never put it together. He showed me two frames of the Orion Nebula, same camera, same settings, and the second one had pinpoint stars. If you shoot from home, have you checked what warm air is drifting through your line of sight?