Light trails

Equipment Needed

Camera
Tripod
Remote Shutter Release (or timed delay)

Introduction

So here we are at night – on a rooftop in Shanghai, China, with an incredible view beneath our feet. The only challenge is, how to best capture it – we have bright highlights, dark shadows, moving light trails from the cars and changing colours on the “rainbow road” of the city’s Nanpu Bridge. That’s a lot of mind-juggling to do before we get started!

01

SETTING UP THE SHOT

In this shot, there are three opposing challenges:


1.We need to keep the shutter open long enough to capture the long light-trails of the car headlights and rear lights as they follow the circular road.


2.We need to keep the shutter speed fast enough to not allow the rainbow colours to change too much – if the camera sees all the colours of a rainbow from one point, it will simply expose it as white light (remember, light is additive – R+G+B = White)


3.We need the overall scene to expose correctly and capture all the details in the streets while not over-exposing the highlights themselves.


So, some of this comes down to trial and error – and a little bit of practice. In this case, 35 seconds was the magic number to allow enough traffic to move in order for our light trails to appear, while not being so long that the rainbow lights on the road would “wash out” to white.


Using an aperture of f/11, at ISO35, with that timing gave just enough to the shadows to bring out the details while not quite clipping the highlights in the concrete towers.

02

CAPTURING AND IMPROVING THE SHOT

Be careful shooting at rush-hour – cars that start and stop are a nightmare for smooth light trails!


I’m always looking out for an indicator signal (with its yellow dashes) or a police car in the frame with its red and blue Morse code streak across the trails – they can be annoying, or an interesting feature, depending on how you feel at the time.


This is a true “expose to the left” situation – while it’s normal for the individual light trails to be over-exposed, we need to be able to separate them to see that they are different vehicles. Aim to slightly underexpose the base image and use the dynamic range of your camera in post-processing to pull up the shadows.

03
POST-PROCESSING

In the raw image, the towers seemed a little bit overexposed, but the dynamic range of the camera soon delivered the shot once “highlight recovery” was enabled in Capture One.


Using a base reference iPhone photo, I could match the white balance to the actual evening, and boosted the contrast a little to ensure the image really “popped” on-screen.

How to compose a nighttime cityscape

Dark scenes