About shutter speed
The basis is that the aircraft movement when the shutter is open must be minus than the pixel size at the scale image sensor.
Example
ground velocity= 20m/s, height =200m, shutter speed = 1/200s, focal length =28mm.
s=vt=20x1/200=0.1m, on the ground
at image scale.
photo escale=focal length/height=0.028/200=1/7142
so movement at camera sensor scale is
s-camera=0.1*(1/7142)=0.000014m=14 microns, so if your camera pixel size is bigger than 14 microns the photos aren´t blurring
Check your: sensor & pixel size, height and average cruised speed to compute the best shutter speed (fixed). Take this suitable configuration: the major time shutter possible, bigger sensor size, the minor ISO speed and high f-number to get the best results.
The extended paper
https://www.asprs.org/wp-content/uploads/pers/2005journal/november/highlight1.pdfhttp://www.asprs.org/a/publications/per ... light1.pdf