Saturday, February 13, 2010
A single 6 sec shot results in maybe 1 or 2 "car trails" which do not travel through the entire shot. If I were to adjust the aperture such that I could get a much longer exposure then the car trails themselves would be dim and barely show up. Also on long exposures noise can become an issue, by stacking the photos, you end up with less noise, although you do get the odd gap in the trails, which you may notice in this shot. This occurs while the shutter is closed between shots.
To make this method of shooting work effectively I would recommend getting a cable remote for your DSLR which has a button lock down feature. This will keep the shutter button locked down, without you having to sit there with your hand on the camera.