When I first started in photography one of the shots I was immediately attracted to was light trails. In a time before the Internet, these great looking shots would often adorn the front covers of the big photographic magazines.
They were not as easy to do as I originally thought. Being shot on film I needed to learn about such exotic things a correcting colour with filters and reciprocity failure. These days shooting light trails is, thankfully, much simpler.
There are, however, a few dos and don'ts that you need know to get great looking light trail shots.
What Equipment Do You Need?
Pretty much any modern DSLR or Mirrorless camera is going to be just fine. It's best to have a remote control for the camera, either wired or wireless. Lens wise, light trail shots are often best suited to wide angles but that does not preclude using a longer telephoto lens for a more compressed looking perspective.
Your lens does not have to be particularly fast, shooting at wide apertures can introduce flare. It’s also a good idea to take along a decent lens shade/hood
Of course, a good steady tripod is an absolute requirement as is a good quality head. I find ball and socket heads are the best option as you can quickly make micro adjustments and then lock the camera solid. You can add further weight to the tripod by hanging your camera bag on it.
Lastly, a good long exposure calculator app for your smartphone is a good idea. These will often have a specific section for light trails shots.
Time of Day
When its dark of course! Except that’s the simple answer. The vast majority of light trail shots are of car headlamps and tail-lamps. The very best time to shoot these is the evening blue hour.
This often coincides with rush hour traffic giving you plenty of car lights to work with. The beauty of shooting the blue hour is that you will still have definition in the surrounding streets and buildings as well as a beautiful midnight blue sky to offset the yellows, whites and reds of the light trails.
For obvious reasons, cities are the best locations to shoot light trails. The shots themselves convey the sense of motion and frenetic energy of most cities. You are looking for locations where the traffic will flow freely and not back up past your viewing point.
Busy junctions are often good locations, the junction area often remaining free of backups but also giving light trails from different. Beyond the city, shooting motorway/highways from atop bridges can give some fantastic images.
If the road curves in the distance, even better.
Getting the Shot
To avoid issues with colour balance it's best to shoot RAW. You can also shoot RAW + JPEG as the JPEG file will give you a good reference from which to work in post-production. If shooting RAW you can comfortably use auto white balance.
You will want to keep your ISO as low as possible, usually, 100 or 200 ISO is the base. You can choose Shutter Priority as an exposure mode but I tend to prefer shooting Manual. This allows me to stop down to f5.6 or f8 and reduce any internal lens flare.
If your lens has stabilisation, make sure it is switched off. Even on a tripod, stabilisation will continue to make micro adjustments leading to a loss of sharpness.
The big question, of course, is how long should my exposure be? There is no definitive answer to that. It depends on the light levels, the amount of traffic passing and the amount of ambient light around.
The best option is to experiment, try shutter speeds from 15 to 30 seconds with the aperture between f5.6 and f8. As you shoot more and more light trails you will get a feel for what the best exposure will be.
When you make the exposure, avoid any direct contact with the camera by using your remote release. If the release is wired, keep it in your had during the exposure, the act of dropping down may be enough to introduce camera shake.
If you are shooting with a DSLR and your camera has it, use the mirror lock-up mode. This will help mirror slap, another source of degraded image quality.
Thinking Outside The Box
While 99% of the light trail shots we see may be of cars along roads, there are other options. Tour boats on rivers in the evening tend to be well lit and can make great subjects. Shoot them from a river bank with an interesting background or from a bridge as they pass underneath.
If you are into aviation, aircraft light trails can also make an interesting subject. You might need to use slightly shorter shutter speeds due to their high speeds.
You can also create your own light trails with a torch or even a smartphone. Set the camera to countdown and get in front of the lens and paint your own light trail creations.
Light trails can make fantastic shots and because of their technical requirements, they can also be very educational. Using some of the tips above, why not head out and see what you can capture, planes, trains automobiles or even your iPhone’s screen.