Light trails created using long exposure are cool effects which all photographers are interested. Light trails or light streaks are created by capturing headlights or tail lights of vehicles at night. In this article we will see the nuances of capturing light trails using long exposure.
Preparation of equipment for light trails
Tripod. A must to capture light trails. Shutter is going to be open from anywhere between one second to six seconds and it is difficult to use a DSLR without a tripod. The tripod should be stable enough to absorb all vibrations and the weight of the DSLR with the lens
Shutter release. A cable release or remote is a good option as it allows you to stand away from the camera. It also takes care of any vibration arising out of pressing the button on the DSLR. Alternatively you can use the delay timer on the DSLR.
Lens hood. Since a lot of dim light is going to be captured, the photo can get ruined easily with ambience light or lens flare from light sources facing the lens.
DSLR. If using DSLR, it has all the settings to create light trails. But nowadays, even advanced point and shoot cameras allow control over shutter speed to give long exposure.
Settings for light trails and their explanation
Long exposure is achieved by using slow shutter speed, usually more than one second. DSLRs give control over shutter speed. In shutter priority mode, the aperture is set automatically. If bulb mode is available, one can have control over how long the shutter will remain open. Use of shutter cable release or remote release is highly recommended, if using bulb mode.
In shutter priority mode, the camera may not give the desired results by auto settings of aperture. In such cases it is recommended that you go to manual mode to have control over both shutter speed and aperture. Using higher f stop number gives the star effect to stationary lights. Use aperture settings between f8 to f16 to get star effect or star burst.
Exposure compensation need to be set carefully to avoid over exposure. More the length of exposure, lesser the exposure compensation. Overexposure can be adjusted in post processing. Exposure compensation settings are also dictated by ambience light and how well illuminated the background is.
Location. A foot over bridge or FOB is the best place to capture light trails. While on a flyover, it is risky in the night as drivers wont be see you easily in low light till they come very close. Other options can be buildings overlooking the road or similar vantage point. If you are located perpendicular to the road, then headlights of incoming traffic will get overexposed as they will appear stationary to the camera lens.
Other points related to long exposure
Choose the background carefully as it should be able to add value to the light trail and not over shadow it. Incoming traffic will give white trail and traffic moving away will give red trail, but you might get some multi color by using yellow turning lights at turns or interior lights of a bus or metro train.
In dwindling daylights after the vehicles switch on their head lights on the road, you can get much better photos rather than late in the night in pitch dark where you will have no background at all.
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