Framed and Exposed: Eine Kleine Nachtphoto

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Although, as photographers, we can be snobbish and poetic about light, it's important to remember that just because it's dark outside doesn't mean there's no light. The light at night has a particular quality that can be extremely enjoyable to work with. The most obvious difference, of course, is that there's far less of it. The light that is there is almost always artificial, so night photography is akin to indoor, low-light photography. Fortunately, a good digital image sensor is much more light-sensitive than even the speediest film. Granted, there's a broad range of low-light quality to be had from a digital camera, but in general, they're well-suited to shots in the dark.

Flash Photography
Flash photography is a subject unto itself, and I'm not going to spend a lot of time talking about it in this article. I will say this: When shooting in low light, many people immediately assume that they must shoot with a flash. But most of the photos I'll show you in this article were not achieved with a flash, but through long exposures.

For most extremely low-light work, the built-in flash on your camera will be far too limited in range and power to be useful. A flash has no problem illuminating what's near-by. The problem is that because the flash requires such a short shutter speed, your camera underexposes everything that's out of flash range, resulting in a well-exposed subject sitting on a field of black.

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Shooting with just a flash gives you a well-exposed subject, but not enough background.

Most cameras these days have a "slow-sync flash" feature that combines a flash with a long exposure, to yield a picture with a properly exposed foreground and background. These features are sometimes referred to as "Night Portrait" or "Night Landscape".

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A slow-sync feature combines your camera's flash with a long exposure to produce a well-exposed foreground and background.

Night modes are also good for low-light portraits, but you must be sure to warn your subject to hold still until after the exposure is completely finished. Often people start moving after the camera flashes. With the long exposure, this will result in a blurry image.

Slow-sync flash images can sometimes look a little strange because the foreground is lit with one color of light -- white -- while the background has the reddish tinge of a low-light long exposure. And because of the long exposure time, moving background objects will be blurry, and if you're not shooting from a tripod, there's a chance that the entire image will be soft.

Sometimes, your camera's slow-sync mode will choose an exposure too short to adequately render your background. Because cameras don't allow exposure-compensation adjustments when in slow-sync mode, you might not be able to remedy the situation. If your camera has a shutter priority mode, though, you might be able to use it in conjunction with your camera's flash. Switch to shutter priority, set for a long exposure, and then activate the camera's flash mechanism.

For more interesting results when shooting in the dark, it's almost always better to do it the hard way. Forget the flash, forget the slow-sync mode, and go with a really long exposure.

Doing Time at Night
The human eye is dramatically more sensitive to changes in brightness than to changes in color. (JPEG compression exploits this by throwing out color that your eye probably can't see anyway. Brightness information is always preserved, though.) The majority of your eye's light sensing mechanism is composed of rods, the luminance-sensing part of your optical mechanism. While your color-sensing cones are gathered near the center, focused part of your vision, rods are spread deep into the periphery of your field of view. In fact, if you're ever walking outside in extreme darkness, try to tune in to your peripheral vision. Keep your eyes pointed straight ahead and focus them on something far away. Then pay attention to what you can see at the extreme edges of your field of view. You'll probably find that you can see things on the edge of your field of view -- which is completely rod-driven -- that vanish when you look at them directly with the less-sensitive cone-driven part of your eye.

Your eye also does an extraordinary job of interpreting colors under different types and intensities of light. While your color vision may wane in low light, for the most part colors still look fairly accurate.

Unfortunately, your camera doesn't perform nearly as well as your eye on any of these counts. Though a digital image sensor is very light sensitive when compared to film, it can't gather light nearly as quickly as your eye. In addition, low light -- particularly low light in a city where there are many different types of artificial light sources -- confuses your camera's sense of color, resulting in images with strong yellow and red casts.

However, your camera can do something that your eye can't. It can gather a whole bunch of light to create one single image. And because of that, it's capable of seeing a world that is often invisible to your eye.

Equipment
Though it's possible to shoot good low-light handheld shots, for most subjects, you'll need a stable tripod. It's also a good idea to bring along a small flashlight. A cable release, remote control, or self-timer can make the difference between a sharp and blurry image. You can use any digital camera for night shooting, but you'll be best served by a camera with the following features:

  • The ability to shoot exposures up to 30 seconds long (you'll rarely shoot this long, but it's nice to have the option).
  • The ability to adjust the camera's ISO. Flexible ISO choice is critical for certain situations. You'll want at least 100-400, preferably 100-1600.
  • A slow-sync shutter mode if you want to use a flash.
  • A shutter priority mode (not necessary, but it will give you maximum flexibility).
  • A tripod mount. Some small cameras don't have them.

Ideally, you want a camera that delivers very low noise at higher ISO settings. As you increase ISO, your images will get noisier. At the very least, you want a camera that yields low-noise images up to 400 ISO, but there will be times when you'll need to crank it higher.

You'll probably also want a camera with an optical viewfinder. In low light, LCD viewfinders and electronic viewfinders are often invisible. Some cameras offer special low-light options that increase the gain in the viewfinder. If yours doesn't, seeing what's in the viewfinder will be difficult. It's not a deal-breaker, as you can always shoot test shots and use them to judge how to correct your framing, but it is an inconvenience.

Finally, you'll need subject matter.

Illumination
One of the great things about night photography is that subjects that are boring in daylight can become far more interesting when the sun goes down, largely because of the way they're lit. That's why just about any location is a potential bonanza of interesting low-light subject matter.

In some regards, night photography is akin to black and white photography, as it's often simply about luminance. The flower shown below was sitting in the middle of a dark sidewalk. However, it had grown just tall enough that it was being lit by a street lamp from across the street.

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Luminance plays a big role in night photography.

In reality, the image was not as starkly contrasty as the image shown here. Figure 4 shows a more accurate shot of what it looked like as I was walking down the street.

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Though not quite as dramatic in real life, the luminance difference in this flower shot is still pretty obvious.

I figured that it would be possible to get a good black and white shot of the flower against an extremely dark sidewalk, something that you can't do in the daytime.

This image was shot from a tripod using a Canon EOS 20D with a Canon 24-85mm lens. On the 20D, there's no perceptible difference in noise between ISO 100 and 400, so I set the camera for 400, as that shortened my exposure time by 2 stops.

I shot this image using the straight program mode. It was a calm night, so the flower wasn't swaying in a wind. Its tiny bit of motion added an interesting slight, hazy blur. I shot one image at the camera's default exposure and then another over-exposed by two stops. I find that the most cameras calculate a base exposure that's too dark for most night shots, so I typically shoot a couple of extra frames, each a little more overexposed.

Since night scenes are often very low contrast, you need to keep your eyes open for subject matter. Areas of bright contrast are often few and far between, but they can make interesting subject matter.

"Wrong" Lighting
Because a camera can gather light for a long time, it's possible to create photos that are much brighter than what your eye could normally see. Good digital cameras are especially adept at shooting long exposures without turning the images to unbearable masses of grain and noise. It's possible to shoot scenes in extremely low light that appear almost as if they were shot in the daytime.

Below, you'll see an image I shot in the middle of the night. All of the illumination in the scene is coming from a street light that stands just out of the frame. Because the camera did such a good job of gathering a lot of light, the image doesn't necessarily look like a night photo, except that the shadows are wrong.

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At first glance, you might think this image was shot in the day.

The brain is used to light coming from above. In this image, the light is coming from the side, and slightly low, making for a slightly surrealistic effect. It's helpful to first find a bright light source, then start looking for likely subject matter nearby.

The image in Figure 5 was colored by hand, using a very simple technique that you can read about on my site, Complete Digital Photography.

Focusing Trouble
Most digital cameras use a contrast-detection autofocus mechanism. The reasoning goes that an area with more contrast is more in focus than an area that's blurred out to very little contrast. The trouble with contrast is that it requires light, something you're short on when shooting in the dark.

Your camera might have trouble locking focus when shooting at night. When you press your shutter button halfway down, the camera's lens will focus back and forth for a bit, and then it will give up. You'll never hear the beep or see the light that indicates that the camera is ready to shoot. There are a couple of ways around this problem.

If your camera has an autofocus assist lamp, you can activate it. Some cameras use their built-in flash as an autofocus assist, and may not let you activate the assist without also firing the flash during the picture, which is probably not what you're looking for. On the EOS 20D, the Auto mode uses the flash as a focus assist. I often switch the camera to Auto mode, half-press the shutter button to get the camera to focus using its flash focus assist, then switch the lens to manual focus and the camera back to Program mode. As long as I don't move the camera, my focus will still be accurate.

If your camera doesn't have a focus assist light, or if your subject is too far away to be illuminated by it, you can try a few other tricks.

For the picture below, I tilted the camera down to get the camera's focus target on the bright light behind the bars. Because it's a high-contrast area, the camera had no trouble focusing. I switched the lens to manual focus mode to hold that focus, and then re-framed my shot and started shooting. If your camera can't switch between manual and auto focus like this, then you'll need to point your camera at a high-contrast area, half-press the shutter to lock focus and then, while still holding down the shutter button, re-frame to your desired composition and shoot.

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A San Francisco police station at night. I used a 1.3-second exposure.

For shooting flowers and other up-close subjects, I'll often shine a flashlight into the scene to create some contrast. It's usually enough to allow the camera to grab focus.

Because you'll be using a long exposure, keeping your camera steady is essential. In addition to a sturdy tripod, use your camera's self-timer, or a wired or wireless remote control to trip the camera's shutter. If you're shooting with an SLR, check to see if it has a mirror lock-up feature. This raises the mirror and waits a moment before opening the shutter, to ensure that mirror vibration doesn't shake the camera.

Because you'll typically shoot at or very near bright lights, you might face lens flare troubles. Even lenses that never produce flare in daylight shooting can yield flare troubles when shooting at night.

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This shot of a manhole cover is problematic because of lens flare.

It can be extremely difficult to see lens fares at night in the viewfinder. If you're shooting directly into a light, it's worth taking a test picture -- a bright, overexposed one -- and then looking at it in playback mode. Zoom in on the image and hunt for that flare.

If you find a flare, you have several options. You can attach a sunshade, if your lens has one; you can shield the lens with your hand, just as you would in regular light; or you can try to reframe the shot or reposition your camera. If you can get your lens at a different angle to the light, there's a chance the flare will go away.

Note that your camera will almost always be shooting with its aperture wide open. If you're shooting with a digital SLR that has an APS or full frame sensor, it may yield a fairly shallow depth of field. On a point-and-shoot digital, this will be less of a concern because of those camera's small sensor size.

Since I knew I wanted very deep depth of field in the manhole image, I switched to aperture priority and selected f16. I then used exposure compensation to over-expose the image and shot using the camera's calculation of 30 seconds.

Exposure and Color
Because of the strange lighting conditions, you can often shoot very different, very interesting color at night. However, your digital camera's white balance mechanism will yield extremely yellow/red color.

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Like all low-light images, the camera erred on the yellow and red side in this image.

Though you can get around this in the daytime with manual white balancing, that's not so feasible at night. It's better to shoot in raw mode, if your camera has one. With raw mode, you can easily adjust the white balance of your image after the fact to restore accurate color. However, though you can often restore white to true white when shooting in raw, you may find that a little bit of extra warmth is appropriate to the image, since our eyes are accustomed to night scenery being somewhat warm in tone.

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Here's the same building after I adjusted the raw file.

Because correcting bad white balance is extremely difficult in a JPEG file, it's much better to shoot Raw when trying to capture color. With a JPEG file, once you've restored the shot to reasonable color, you'll have very little image data left to play with if you want to make other changes.

To shoot the rose image below, I encountered almost every difficulty I've mentioned so far. First, the camera had difficulty focusing, so I had to use a flashlight to get the autofocus mechanism to lock.

Next, the camera's default meter reading yielded an exposure that was far too dark. Just as with daylight shooting, your goal when shooting at night is to capture as much image data as possible. A quick glance at the camera's histogram, after shooting an image at the default exposure, showed an under-exposed image with very little data. A few more histogram tests revealed that simply dialing in a +2 exposure compensation gave me a broad range of tones without clipping either the shadows or highlights.

I had been intending to shoot at ISO 400, but by the time I'd focused and figured out my exposure, the wind had picked up, and the rose started to blow around, making my 1-second exposure time a little unreasonable. I cranked the ISO to 1600 to facilitate a faster shutter speed, and I used shutter priority to capture an image at 1/20th of a second. The histogram showed an image with much less tonal range than I wanted, but I at least had a safety shot to work with if none of my other exposures were successful.

I dialed back down to ISO 400 and went back to my original exposure plan. Fortunately, the wind died down and I was able to fire off a few shots, one of which was sharp enough to keep.

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This image was partly planning and partly luck-- planning of exposure, luck that the wind stopped blowing. I shot it in raw, so it was easy to restore accurate color.

Or Just Fake It
Oddly enough, taking your camera into a world with less light might just reveal a bunch of photographic opportunities that you've never seen before. Though the margin for error when shooting in the dark is much narrower than daylight shooting, the histogram, ISO capabilities, and instant feedback provided by a digital camera make night shooting a less perilous endeavor.

If all of these recommendations and guidelines sound intimidating, just relax. You can often get good results without all this extra thinking, as shown below, a handheld photo shot without any gnarly computation or concerns.

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The most important thing is to try shooting --any kind of shooting -- at night.

Read more by Ben Long.

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