No Light, Low Light, No Problem: Environmental Portraiture at Night
Photography is all about light, but what do you do if there isn't any?
In this article you'll learn about the aesthetic and technical challenges of photographing at night and the strategies and techniques to overcome them. The skill of photographing at night is useful for journalism, documentary, outdoor weddings, dark indoor venues, or any time where you can't see but still need to make a photo.
Zero Ambient Light
To give you an idea of our starting point, here's what the scene in our example looks like at 6400 ISO, illuminated by a single flashlight.



The happy wedding couple wanted an engagement portrait in a park enclosed by trees. The spot we chose was so enclosed we couldn't even see the street lights. It was almost completely dark.
Damn You, Inverse-Square Law!



I set up a flash with a beauty dish a few feet from my subjects and made the photo above. They are in the middle of a clearing in the park but they might as well be on a black background. There's no context.
The problem is the Inverse-Square Law. As light travels from a point, like your flash, it spreads out in a wave in all directions. When the light is placed close to the subject, the distance the light has to travel to reach the rest of the scene and then bounce back to the camera is relatively far compared to the distance it has to travel to bounce off of the people and back to the camera.
What this means is that the amount of light that bounces back from the background in a situation like this is relatively low, creating a high-contrast exposure like you see above. This isolates the subject from the background. It's a look that works well for dramatic sports portraits, documentary, or photojournalism, but it wasn't the soft romantic lighting I was going for.
Light the Environment Instead
Next I moved the light back 20 feet and increased the power output. Now the relative distance from the light to the subject and the light to the background is much closer. The subjects are still more illuminated than the background, but the lighting is better balanced.



Secondary Lighting: Complete the Look
In the example above the light behind the couple could easily be moonlight, and it looks like they are lit in front by that lamp they brought. Including a light source inside the photo like this can help fool the eye into thinking it was lit with ambient light when, in fact, it wasn't.
On the left, I set up a flash on the ground near the lamp, just out of frame, with an orange gel to light them up with warm-colored light from the "lamp."
If you put a second light in the background, inside the frame of your shot, you can fake it to look like moon light, or even sun light. This is what I did on the right. Be careful to place it where the moon would realistically light up a scene. Then simply retouch out the light stand, leaving the flare in.






Use Ambient Light to Your Advantage
The example above was extreme. In most situations there is probably still some ambient light in your scene. If you see light in your environment, don't be afraid to crank up the ISO and use the existing light as your main source and your flash to stop action or fill things in a little. In the example below I made use of Christmas lights and light from the streetlights. The couple are lit entirely by ambient light.



If you look for opportunities to use the ambient light you'll definitely find them. Ambient lighting can create a wonderful casual, natural feeling. It's not perfect, but that's part of the charm. Of course it's best to plan a night shoot feeling comfortable with your flash, just in case, but if you find lighting opportunities that don't need the extra setup, all the better.
Controlling colour is an important part of creating a convincing night portrait. Flash heads emit light in the daylight spectrum, normally in the range of about 5000 to 6500 Kelvin. Most light sources at night are much warmer, or more orange. Use lighting gels to adjust the colour of the light source you can control, your flash, to match the ones you can't.
Critical Focus
Getting proper focus when you can't see is a real pain. Pretty much everyone relies on autofocus today, but most cameras don't autofocus well in low light, low contrast situations. What is there to do?
First, you can use the live view on your LCD. If you are using a tripod, this method works pretty well. Zoom in on the LCD and tweak your focus until it's right.
Second, use a flashlight. I have several small flashlights that are always in my camera bag. If you aim a flashlight at the subject, then your camera can get proper focus and you're free to fire away. If you are using flash, a small flashlight like the one I have doesn't affect the final exposure, so you don't even need to turn it off. If you are not using flash, click it on when you need the assist, then off before you take the photo.



The third method of getting proper focus is the motor drive method. This method works in a pinch, and only works in constant light situations. Stand with your feet apart and get to where you think your subject is in focus. Lean on your front foot until you know the subject is out of focus. Now hold down your shutter and take a burst of photos while rocking to your back foot, then again while you lean forward, until you're sure you have a sharp frame. It's certainly not ideal, but it works in a pinch.



The fourth focus method is to use your flash. Most modern speedlights (and flash commanders) come with an "autofocus assist" feature: the flash emits a beam of red or infrared light when you half-press the shutter button. This beam creates a grid of light on your scene that the camera's autofocus sensors can pick up. This usually works best in autofocus single (AF-S) mode.
If you want to use the focus-assist but don't wont to use the flash, most units have a way to set the mode to focus-assist-only.



There are Photos to Make Even When You Cannot See
We've covered a few different ways to light your subjects at night, as well as a few different ways to get them in focus, and some of the aesthetic concerns of using flash to illuminate everything in your scene. In my opinion, artificial lighting is best when it is mixed minimally with ambient light. Find ways to be clever and make your composition look like it's ambient lighting and your photographs will feel much more cohesive.
Keep Learning About Light
Pedro Isztin's course, Environmental Portraiture, is a great introduction to naturalistic portraiture with environmental light. Highly recommended.
Finally, here are a few more tutorials about portrait lighting in environmental situations: