How to Shoot Long Exposures
Long exposure photography is gaining a lot of interest with the increase in long exposure videography. It seems like every day there is a new video being passed around the internet showcasing a city's skyline at night, morphing from still buildings to dancing lights (Josh Owen's timelapse of New York City is particularly enchanting). Lucky for still photographers, long exposures can capture that same energy in one steady shot. There are different techniques to capturing a perfect long exposure shot in the night and in the day. Navigating and capturing the right amount of light can be the most difficult. But with the right equipment, a lot of patience and some know-how, you can get a quality image. (All images used in this article shot by Alex Wise, Tasmanian based amateur photographer.)
Unlike still quick exposure photography, there is very little wiggle room in long exposure photography. Stabilizing the camera is crucial thus necessitating a tripod or a tripod substitute. There are plenty of Make Your Own Tripods sites out there, some using crutches and others using run-of-the-mill Home Depot scraps. Or you could spring for a really nice tripod running you anywhere between $20 and a couple thousand dollars. Whichever method you prefer, you are going to need a tripod. It eliminates camera shake, the archenemy of long exposure shots. You also need a camera that has an adjustable shutter speed. It would be even better if one of those speeds was BULB. The BULB speed leaves the shutter open for as long as you depress the shutter button. Some photographers keep away from the shutter button entirely to keep long exposure photography a totally hands off experience.
You can hook up a remote to your camera; after setting your camera up on the tripod and focusing on the subject, you can step away and remotely fire off the camera. If you don't have a BULB setting or a remote, than play around with the shutter speeds. You don't necessarily need 30 seconds worth of exposure time. You would be surprised how little light is needed to hit the sensor in order for a long exposure shot to turn out correctly. Once you find the correct combination of ISO, shutter speed and aperture, hold your breath and take the picture. Seriously, holding your breath means you move less. The less you touch the camera, the less you shake the camera. Another sure fire way to get that sharpest, stillest shot possible is to use the self-timer. For whatever reason, people don't think of that one very often (hence it being at the end of this paragraph) but long exposure photography is the prime time to use it.
Lengths of Exposure
There are three general lengths of exposure: short, medium and really drawn out. Just kidding; that last one is just called "long". Short exposures usually only last a few seconds and are best utilized during the day. It is this length of exposure that shows blurred movement; movement from an object (such as being on a boat) or movement of an object (such as being on the shore shooting a moving boat). Medium length exposures last around a minute or less. Shooting traffic or moving lights in the sky (not stars) is a good time to use medium length exposure times. It is long enough to get all the light in the shot but the light doesn't wash out or show up as super highlighted points. Any objects that are moving, such as cars, will show up only as streaks of light and not the cars themselves. Long exposure times have an indefinite end. Michael Wesley is famous for his two year long exposures of the destruction and rebuilding of huge skyscrapers the world wide. Now that's long exposure photography.
Shooting Long Exposure during the Day
If you walked outside at midday to shoot a long exposure of a bird flying by, you might find that it is a white wash. You think to yourself: the sun is too bright for a slow shutter speed. Wrong. The sun is bright but there are ways around that. The key is in the aperture. When you use a larger aperture, less light hits the sensor than a smaller aperture allowing you to expose the film for longer periods of time without washing out the shot. In the image below, the film was exposed for five minutes at an aperture of f/9. But Alex Wise had another trick up his sleeve. He utilized a Neutral Density filter. ND filters are neutrally colored filters that fit over the end of your lens. They block out a significant amount of light in measurements of one stop to thirteen stops; each increase in stop doubles the amount of light blocked thus doubling the amount of time you can expose the film. For a more in depth look into ND filters, check out Steve's explanation here.
Shooting Long Exposure during the Night
If you didn't go out and buy a tripod for daytime exposure, you are going to need to now for nighttime exposure. Your camera is so sensitive to every light source but equally sensitive to when the camera moves. One hiccup, one sneeze or one deep breath while holding the camera will ruin everything. Besides, you don't want to hold the camera for twenty-seven minutes just to get one shot. When choosing the settings on your camera for a night shot, spend some time experimenting. From the start, you will need a low ISO in order to get the sharpest image with the least amount of noise to distract from the image. However, if your camera only allows for a few seconds of exposure time, the ISO will need to be bumped up in order to compensate for the small amount of light exposure. Also set the focus to All or Infinite. During the day it is fine to pinpoint one object to focus on, but nighttime long exposure shots need as much focus help as possible. Maximum focus points combined with large aperture settings will ensure a crisp image. As with any type of photography including daytime long exposure, shoot in the RAW. This will give you unadulterated results that are easily manipulated if needs be in post-production.
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