You’ll want a long enough exposure to walk fully around the car(s) in the shot before the shutter closes. In the photo above, 15 seconds was plenty of time to make a circle around both cars with ...

Continuous exposure to blue light while driving therefore appears to be as efficient as coffee for fighting sleepiness at the wheel, as long as this light does not hinder the driver.

For the XJ220, I added an off-camera light source, holding the LED wand stationary for a long enough exposure to reveal the ground and give the car a long shadow.