Long exposure is something every photographer has tried at least once. In simple terms it involves leaving the shutter open for a long period of time in order to capture more light than our eyes perceive. The longer the shutter is left open the brighter the image will be. If the light source moves while the shutter is open you will experience blurring of that light source. With me so far?
The simplest way to begin experimenting with long exposure is to shoot a night time landscape. For this you will need a camera with manual controls, a tripod and a remote or cable trigger. The trigger is to prevent the camera being knocked or moved when you take the shot; with long exposure the slightest camera movement can ruin a great shot.
Next, take your gear to a spot which you think would be interesting to photograph at night. Popular choices are beaches, city rooftops and suburban lookouts, as these locations typically have distant light sources which you can utilise. It’s a good idea to check out the area and scout a location that not only looks good but is practical and safe; make sure there are no hazards around to ruin your night!
When you have picked the spot and set up your gear you need to work out your settings. This can take a lot of trial and error, and can depend entirely on how long you are willing to wait for an exposure. If you are shooting landscapes then you should be able to throw your aperture wide open, to let in as much light as you can, but be careful with your focusing. Your ISO settings can be tricky, as some cameras get very grainy at a high level. As sensors improve this is becoming less of an issue however I suggest you try some exposures and see how you feel; if it’s too grainy dial your settings back a little (800ISO is a good place to start).
Next, shutter speed. Firstly you need to judge how much light you have around. If there is a streetlight nearby or in the shot you probably won’t need too long an exposure, however if you only have moonlight or even just ambient light you will need the shutter open much longer. Many cameras will allow you to have the shutter open for up to one or two seconds but if this isn’t enough you may need to try the bulb (B) setting. This lets you hold the shutter down for as long as you need, and works especially well when you use a shutter release cable with a locking mechanism.
The great thing about digital photography is being able to see your exposure right away; use this to your advantage by checking your exposures and adjusting accordingly. Experiment with different exposure lengths to get the perfect shot. Keep in mind that you will very rarely be in a situation where there is NO light available, you just might need to keep that shutter open for a very long time. Also keep in mind that what you see when you’re setting up your long exposure shot isn’t necessarily what you will get; your light source can drastically alter the exposure and even colour of the shot.
Once you have got the basics down with a landscape you can try painting with light. One simple way to do this is to take photos of night time traffic. You will notice that vehicle lights will create a bright trail across your shot, and if you leave the shutter open for long enough you will get the light trail but the vehicle will not be visible. This is because the light is bright enough to reach the sensor but the light bouncing off the car is not. Another fun way to paint with light is to use torches, flash units, glow sticks and other light sources to illuminate parts of your shot briefly during your exposure. Give it a try – what kind of effects were you able to produce?