Car Light Trails

Need some photography ideas for night? Try shooting some creative light trails of cars using just a camera and tripod. The whole idea behind this is to take long exposure shots of moving cars where the head light and tail lights of moving cars will form light trails on the camera sensor.

EXIF: ISO100 and F/11 at 10 secs (0 EV).

Locations

Typically, light trails of moving cars are taken from a high-level ground (e.g. bridge or from apartment which has a nice street traffic view) where a long stretch road with unobstructed traffic can be seen. The effects would be exceptionally nice if the roads are full of turns and bends.

However, shooting car light trails at ground level view e.g. traffic junctions, could also produce very interesting results with the lights of cars turning in different directions. Do bear careful to observe the traffic if taking near roadside.

Camera Settings

There is no one fixed settings for taking car light trails as it depends on the ambient lighting condition on the roads, so the settings would have to be adjusted accordingly to match the scene ... basically trial and error. Here are a few pointers though:

• Use low ISO 100 to reduce as much noise from the shadows and long exposure.
• An exposure time of 10 secs to 15 secs should be sufficient to capture beautiful light trails of cars. A longer exposure time may wash out the light trails and ended up with thick bands of lights which may not look nice (see photograph below which is shot with a longer exposure compared to the 1st photograph). Once again, it depends on the amount of traffic on the roads.

EXIF: ISO100 and F/16 at 30 secs (0 EV)

• The aperture should be compensated accordingly for the amount of exposure time that will be used. Use the camera's metering to determine the amount of aperture to use. An small aperture of F/8 or higher would be better for a good enough depth of field.
• Switch to manual focus, and focus halfway down the road or on something which you want it to be captured visually strong in your frame.
• Shoot in RAW to allow more control over white balance, exposure, etc. Do note that street lights and car lights does produce a orange cast in the photographs taken.
• Taking car light trails during twilight hours (i.e. when the sun is just about to set) could produced a nice picture with a natural atmospheric ambience light with artificial light trails from cars.

Try Creating a Traffic 'Heat Map'

To create a traffic 'heat map' showing frequency of traffic (i.e. see 1st picture above), I had stacked 6 photographs of the same scene taken with different car light trails and blend them using 'Difference' blending mode in Photoshop to produce an array of colored car light trails. Follow the following steps using Photoshop:

• From Photoshop, select Files --> Scripts --> Load Files Into Stack ...
• Select all the car light trail photographs taken from the same scene and click 'OK'. 
• Once all the photographs are loaded into stack which you can see each photograph as a layer, you will need to change the Blending Mode for each layer to 'Difference'.
• Merge all the layers into one and you have the traffic 'heat map'.

Please visit http://jefzlim.smugmug.com/Themes/Light-Trails for the higher resolution photos ...