Long exposure and tail lights
Actually, it can be headlights as well if that’s more your cup of tea. I prefer tail lights because they have a nicer color and headlights tend to be a bit too bright for that perfect exposure. A friend just asked about the trick of the trade on msn and I thought I’d whip up a quick post about it.
Long exposure and light trails photograpy is really simple and very gratifying, as you get spectacular results pretty much instantly. But to obtain a nice balance between lights and environmental details takes a bit of experimenting.
First of all, it doesn’t do to take a shot in the dark. Pitch black sky and black concrete don’t reflect any lights and will make the photo look dull. You really want detail and a certain amount of light pretty much everywhere in the frame. Therefore, the best time to take these photos, as in any nighttime photography, is the blue hour, that magical little window of time after sunset when the sky is a rich deep blueish purple. This light will also balance the frame so there will be no overly dark or bright spots, which makes a correct exposure much, much easier.
Of course you can break this rule, like I have done many times. On a foggy night, the gazillions of tiny mist drops in the air will spread and reflect the light and give your photos a dreamlike appearance. Or you can venture out on a rainy evening and catch the gorgeous reflections of car lights on the wet asphalt.
When you have found a suitable spot for your photo, a nice street with nice surroundings and a safe place to set up your tripod, you can start thinking about the delicate issue of shutter speed. Some good rules of thumb:
- The more cars drive past during the exposure, the more lights, the more powerful light trail in the photo. On a small street or road, even a single car can produce a good light trail, but I usually jump for joy when I see two or more drive past in a convoy.
- The car(s) should pass through your frame from front to end during the exposure, so the optimal shutter speed would be the amount of time it takes for a car to drive along the part of the road that you are photographing. If the car drives too fast, it won’t have time to leave a significant trail. If it drives too slow, it won’t have time to pass throught the frame, so you’ll end up with a line that ends abruptly half way - not pretty. So have a look at the average speed of the passing cars, then adjust your shutter speed so that a car will have time to cross your frame.
- I always underexpose these photos by at least 1EV, to bring out contrast in the photo. Also take in consideration that a passing car will light up the image, so make sure you count that in when taking a test shot of the empty street to set the exposure values. ISO speed and aperture may have to be tweaked to obtain the crucial shutter speed, but optimally ISO100-200 and aperture f8-f13 yield the best results.
- If you have a polarizer filter, use it to block out disturbing reflections, for example when the car passes under a streetlight that makes its roof shimmer. A filter also makes it easier to adjust the shutter speed to the desired amount.
I’d love to see your light trail photos, so if you have any to showcase, leave the link in a comment here or on my Flickr page. Good luck!