A sharp frozen car and a good motion pan need very different shutter speeds. Decide which look you want before changing autofocus settings—or buying another camera.
See the difference →
The car is the sharp priority. If this is the look you want and the car is blurred, raise shutter speed before changing everything else.
300mm · f/10 · ISO 500. Renzopaso / Artes Max, CC BY-SA 2.0.
The background blur is deliberate. If the whole car dissolves too, move to a faster shutter and rebuild a smoother follow-through.
250mm · f/16 · ISO 200. John Chapman (Pyrope), CC BY-SA 3.0.The frame usually gives you a useful clue. Change one thing at a time.
Move toward 1/1600 or 1/2000 if the car still shows unwanted subject motion, especially on a close fast crossing.
Once your tracking is repeatable, try 1/125 and then slower speeds for stronger background motion.
Keep the AF area simple enough that you can hold it on the car. Vehicle recognition can help on supported bodies, but it is not a substitute for keeping the subject in the active area.
Useful manufacturer references: Nikon panning guidance · Sony motorsport focus guide.
Set the shutter speed the photograph requires, open the aperture as appropriate, and let ISO rise to hold exposure. If you already have enough reach, an f/2.8 telephoto can be a more useful purchase than a longer but slower zoom.
If artificial lighting creates banding, test anti-flicker or high-frequency-flicker settings and different shutter modes on the actual camera before race day.
Where safely and legally permitted, moving the front of the lens closer to the fence, focusing well beyond it, and using a wider aperture can make the fence less dominant. Never put equipment through a safety barrier or enter a restricted area for a cleaner frame.
If the car is too small, look at reach. If the framing is good but night exposure is the problem, compare the f/2.8 path. The Motorsport & F1 page has the current Altech product choices.