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There’s a problem with that ‘bullet in flight’ photo of Trump.
The bullet seems to be flying about twice as fast as it ‘should’ have been. Here’s the math to back up that claim.
I know a thing or two about capturing fast-moving objects— for 7 years or so, I was the founder of a company that created equipment to — among other things — capture bullets in flight.
I was fascinated, then when I saw the photo Doug Mills took for the New York Times:
There’s a problem with the photo however: Something doesn’t add up: The bullet seems to be flying about twice as fast as it ‘should’ have been.
I haven’t seen the EXIF data of the photo, but in a NPR interview, the photographer tells NPR he was shooting at a 1/8000th of a second shutter speed. That seems consistent with the photo: The people in the background are thrown out of focus, which means he was shooting with a long lens (probably a 70–200 f/2.8). To shoot wide open, at f/2.8 in bright sunlight, you’d need to shoot with a very fast shutter speed, so 1/8000th tracks.
(Update: The photographer has since shared the full EXIF data of this image, see below)
Now, it’s possible that perspective is playing tricks of us, but the length of the streak in the photo appears to be around as long as Trump’s head is tall. Assuming he has an average-size head, that’s 18–20 cm.
The bullet flying 18cm in 1/8000th of a second, would indicate a speed of 1,440 meters per second or 4,724 ft/s (feet per second). For 20cm, the same numbers are 1,600 m/s or 5,249 ft/s.
There’s a problem: Whether chambered in .223 or 5.56, the muzzle velocity (i.e. the speed of the bullet as it leaves the barrel) is around 3,200. And most sources say that the shooter was around 450 feet away.
Assuming that the bullet did exit the barrel at 3,200 feet per second, and it did fly 150 yards, Shooter’s Calculator suggests the speed should have been 2,890 or so.
