August 24, 2015

Photography After Dark

Modern digital cameras have amazing abilities to see in the dark better than we can. Even a compact digital camera can make decent night shots. (Cell phone cameras are not as capable.) So what do you need to know to make night photographs? Here are a few of my own tips as well as links to resources with more information.

50 seconds, F/8, ISO 400, 24mm lens
Red Rock Canyon National Conservation Area, Nevada

Turn off the Flash
If you are new to photography and are just learning all the buttons, your first step for night shots is turning off the flash. The camera wants to fire the flash when the light levels drop, but this will prevent the camera from recording anything but the brightest lights in the background. Moving the camera from Auto exposure mode to Program exposure mode (or something similarly named) disables the flash on most interchangeable lens cameras. No flash allows your camera to use a longer exposure time to record the dim night light.

Auto Exposure Mode with Automatic Flash
Las Vegas, Nevada
Program Exposure Mode with No Flash
Las Vegas, Nevada

Keep the Camera Still
The long exposure times required in dim light mean a greater chance of blurry pictures due to camera movement. The best way to keep the camera still is to place it on a sturdy tripod (or any solid surface) instead of holding the camera. If your camera or lens has a motion control feature (such as IS or VR), be sure to turn this off when the camera is on a tripod. Leaving it on will give a blurry picture instead of a sharp one.

Pushing the shutter button can jiggle the camera. So use the camera's self-timer feature, which creates a delay (either 2 or 10 seconds) between the time you press the button and when the camera makes the picture. This allows time for any wiggles to disappear, leaving you with a sharp image.

Self-timer Icons

Or you can use a remote shutter release (cable release) to trip the shutter without touching the camera. Remote releases come in wired and wireless versions. I prefer wired models because I can shoot from behind the camera more comfortably. The wireless sensor on most cameras is on the front (lens) side, which means you have to bend your wrist so the camera will see the infrared remote signal when you press the button.

No tripod
8 seconds, F/4, ISO 80, 28mm lens

With tripod
8 seconds, F/4, ISO 80, 28mm lens

Use Manual Focus
If you are making pictures in a city or other location with artificial light, usually your camera can focus normally. But autofocus does not work under very dim light, such as photographing stars or by the light of the moon. So to ensure you get a sharply focused shot, you need to set the lens to infinity focus. This is usually marked on the lens barrel by the infinity symbol (an 8 lying on its side). There are two ways to accomplish this. One way is to autofocus on a distant object while it is still light. Then turn off autofocus to prevent the lens from trying to refocus in the dark. The other method is to turn off autofocus and manually adjust the lens to the infinity focus distance. You may want to tape down the focus ring so you don't accidentally change the focus in the dark.

1.3 seconds, F/11, ISO 100, 28mm lens, manual focus
Missoula, Montana

Select a High ISO
The ISO setting affects the camera's sensitivity to light. Higher ISO numbers help the camera "see" in the dark better. The more sensitive the camera is to dim light, the shorter the exposure time can be. ISO 800 is much more sensitive to dim light than ISO 100. The newer the digital camera, the better its high ISO settings are at controlling the amount of noise (a sandpaper like appearance in the image). So don't be afraid to try settings as high as ISO 3200 or 6400. At extremely high ISOs, capturing your image as a raw file allows you to better reduce the noise using software.

Interchangeable lens cameras have larger sensors that produce less noise than compact digital cameras. So if you are using a compact model, you may not want to raise your ISO higher than 400 or 800.

1/6 second, F/4, ISO 12,800, 47mm lens
Greenough, Montana

Use a Wide Aperture
The aperture is the size of the hole in the camera's lens. Smaller F/numbers designate larger holes, so F/2 is a larger opening than F/8. Larger holes let in more light and shorten exposure times. You can set your camera to Aperture Priority exposure mode in order to choose the aperture you want to use. Often the widest aperture goes along with the shortest lens zoom setting (wide angle). So if you zoom out (to include more in the scene), the camera will be able to select a wider aperture.

30 seconds, F/4, ISO 1600, 17mm lens
Greenough, Montana

Use a Long Shutter Speed
Even with a high ISO setting and a wide aperture, your exposure times will be long, usually several seconds instead of a fraction of a second. Most digital cameras can time shutter speeds up to 30 seconds automatically. If you need to measure minutes or hours, then invest in an intervalometer. This is a fancy remote release that can be programmed to keep the shutter open for many minutes. You set the camera to Bulb exposure mode for these long exposures and use the intervalometer to time the shot.

472 seconds, F/4, ISO 800, 17mm lens
Greenough, Montana

For more information on night photography, check out these resources: