Just got a used p4pro and not sure what to expect for long exposures. I can get about 1 second nice and sharp but at 3 seconds and above I get horizontal drift lines/blur. I am pretty sure it's from the gimbal since I can see the image drift with the phantom sitting still on a table. I did the gimbal calibration several times and I have the gimbal follow mode off. I also have the stability setting at zero and the exp at 3. Is this just normal behavior or should that 8s really be achievable?