How to Expose for the Night

The metering systems in all cameras are designed for use in daylight conditions. Therefore a meter reading can only be used as a "starting point". There are a few factors in night photography that make camera meters unreliable.

Exposure meters work on the premise that the area being read contains equal amounts of light and dark areas. It can then integrate the reading to a tone of gray. 90% of the time this works fine and experience will tell you when meters will not operate 100% accurately. In much the same way as we've covered earlier in the course regarding tricky lighting situations. For example, large amounts of dark unlit areas with small bright points of street lighting will lead to over exposure.

In the "old days" using film, the photographer could not see the results. There was further issues regarding film that made it more difficult to get good night exposures as we will expand upon later in this lesson. Using a digital camera, simply take a meter reading and take a test shot. If the image is too dark or bright, simply adjust the exposure accordingly until the image replicates the scene.

Bracket Exposures: It is always best to bracket exposures as even with digital cameras, the image on the viewscreen cannot be properly judged. For more on Exposure Bracketing see our range of courses.

You will find that metering off light sources, for example lighted or neon signs will give a much faster exposure then reflected light from street lighting or floodlight. Although a meter reading may be a fair starting point, a certain amount of experience can go a long way. As you gain your experience with night photography you will find that your instincts in estimating an exposure will surpass any camera meters capability.

Exposure Tools

fig n.3 30 Sec. Shutter Speed

There are features on all DSLR cameras and many advanced digital compacts that make photography at night possible. Due to the lack of lighting exposing the image generally takes much longer. This is where the slower shutter speed settings become a valuable asset. Most cameras have shutter speeds up to 30 seconds. Often indicated as 30" on the camera as seen in fig n.3

Here are a few camera features seldom used for daylight photography that are invaluable at night.

Timed Exposure Features

B or Bulb setting - Once the shutter dial is adjusted to "B" or BULB (fig n.3), the shutter will stay open as long as the shutter button is pressed and will not close until the shutter button is released.

On film cameras, one way to see this effect in practice is to open the back of the camera when there is no film in it. Then set the shutter dial to "B" and press the shutter button. The shutter will stay open until you decide to release it. This operation cannot be seen in the same way with a digital camera but the effect can be viewed on the LCD screen after an image is taken. Using this setting may take a small bit of practise because we automatically tend to release the shutter button as soon as we press it.

T or Timed setting This setting is used in a very similar way to the "B" setting and the same effects can be achieved. The difference between the two though is that using "T" the shutter is pressed once and released to open the shutter. The button is then pressed again to close it. The advantage of this over the "B" setting is that the photographers hands are free and the risk of camera shake is reduced. Unfortunately very few cameras have this setting.

When using either setting the timing is done manually by the photographer. Rather than depending on a cameras shutter timer, the photographer must count off the desired seconds (or minutes) the shutter is to remain open. The risk of camera shake, especially with the "B" setting is extremely high.

In order to avoid blur from camera shake using either the B or T setting, some sort of remote release is almost essential.

Sensitivity Ratings: It is a common belief that the lower the available light, the faster the ISO rating needs to be to record enough light. Usually this is true, however, fast ISO settings are not always necessary for night photography.

Normal ISO settings (100 to 400 ISO) can be used successfully. The exposures needed would just be longer, sometimes for several seconds. Hence the need for a sturdy support such as a tripod!

Self Timer: If you do not own a remote release, an alternative is to use the self-timer for tripping the shutter. This only works however for shutter speeds that can be selected on the camera. Most cameras have shutter speeds up to 30 seconds. Note: The B or T settings cannot be used with the Self Timer.

So, put the camera on a tripod, compose the shot, adjust your exposure. When you are ready, set the camera timer, then trip the timer and stand back while the camera takes the shot for you. Remember to wait until the shutter closes before aproaching or touching the camera.

Night Scene Mode

fig n.4 Night Mode

Many DSLR and compact cameras have a "Night Scene Mode" (fig n.4). This allows the user to take photos at night outdoors. The way most of these work is to set the camera to the mode and simply take the picture. In most cases the flash fires automatically to light a subject in the foreground and a prolonged shutter speed will record any ambient light in the background.

Some cameras will allow the flash to be switched off if preferred. On other compact cameras the exposure can be adjusted through "Compensation" to fine tune the exposure. In most instances the exposure would be deliberately over exposed for best results.

The results can vary with this mode depending on the situation and how well the particular camera can cope with the situation. Because of the lack of full control however the results are "pot luck" in the end. Remember though that a tripod is still necessary and using the Self Timer would also be a help for preventing camera shake.