Let's talk about getting the right shutter speed for airshow photography. This discussion is largely seeking or avoiding motion blur.
Seeking opposites for the same event may seem strange, but moving parts on an airborne aircraft should be blurred to illustrate movement, to avoid the parked-in-the-sky-appearance. Primarily, helicopter and airplane rotor and propeller blades appear best when blurred, while non-moving parts look best sharp.
Blur is created when subject details move across pixels on the imaging sensor during the exposure. The movement can be from the subject, the camera, or both, and the movement relationship between the two is what determines the amount of blur.
Higher-density imaging sensors essentially magnify blur, but the final output size equalizes this difference.
Motion rendered large in the frame, close or magnified with a longer focal length, will be stronger than that of the same motion rendered small in the frame. So, subject distance and focal length play into the decision.
When there are multiple movements in the frame, blur differences occur. Turning the zoom ring affects change in all directions, and focal length zooming during the exposure can create a blur that panning cannot mitigate.
With so many factors coming into play, and with those factors changing constantly, airshow shutter speed rules are imperfect. Still, especially for those not regularly photographing airshows (or not having the ability or interest to change shutter speeds constantly during a pass), rules are helpful.
Let's start with capturing the motion blur. Try starting with 1/400 or 1/500 second exposures to blur airplane and helicopter props and rotors. While this speed is a good starting point for motion blur, unfortunately, it is not easy to keep fast aircraft sharp at these exposure durations, and you can expect a high blurry aircraft ratio in the results.
Jets do not show moving parts on the exterior, and they typically move faster. Thus, there is no need to blur any portion of the subject (though a blurred ground background may be desired), and fast shutter speeds are the best choice to stop the motion. Figure 1/1600 or faster.
When jets are flying in multiple directions, as illustrated in this image, the speed and direction of all aircraft in relation to the camera's panning direction must be accounted for, and stopping all the action requires a faster shutter speed than when panning with a single jet or with a formation of jets flying in the same direction. Freezing both planes in the Blue Angels and Thunderbirds opposing pass routines requires an extremely fast shutter speed, considerably faster than the 1/2500 exposure used for this image.
Obtaining fast shutter speeds means higher ISO settings for adequately bright results. As mentioned in the last Blue Angels image I shared, aircraft are not super detailed and the sky lacks detail. This means that noise reduction can be applied without much loss of detail, smoothing the high ISO noise.
Use the rules for insurance level settings and check the results between passes. If you are getting consistently sharp prop aircraft at 1/400, try longer exposures for greater blur (and perhaps pan-blur the ground-based background when such avails itself). If all your jets are sharp at 1/1600, consider trying a longer exposure.
While I'm talking about airshow photography here, the concepts are transferable to other photographic pursuits.