In previous article "Working with short exposures" we talk about taking pictures in a tiny slice of time so we can freeze everything.
Here we will talk about long exposure, what is it? How we can control it? And what we can do with long exposure.
First let's start with what is long exposure.
Long Exposures
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Longer exposures are a doorway into another world, showing us how even familiar scenes can look much different when photographed over periods measured in seconds.
At night, long exposures produce streaks of light from moving, illuminated subjects like automobiles or amusement park rides.
Extra-long exposures of seemingly pitch-dark subjects can reveal interesting views using light levels barely bright enough to see by.
At any time of day, including daytime (in which case you’ll often need the help of neutral density filters to make the long exposure practical), long exposures can cause moving objects to vanish entirely, because they don’t remain stationary long enough to register in a photograph.
Three Ways to Take Long Exposures
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There are actually three common types of lengthy exposures: timed exposures, bulb exposures, and time exposures. The Nikon D3100 offers only the first two. Because of the length of the exposure, all shots with very slow shutter speeds should be taken with a tripod to hold the camera steady.
Working with Long Exposures:
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Because the D3100 produces such good images at longer exposures, and there are so many creative things you can do with long-exposure techniques, you'll want to do some experimenting. Get yourself a tripod or another firm support and take some test shots with long exposure noise reduction both enabled and disabled (to see whether you prefer low noise or high detail) and get started. Here are some things to try:
Here we will talk about long exposure, what is it? How we can control it? And what we can do with long exposure.
First let's start with what is long exposure.
Long Exposures
-------------------
Longer exposures are a doorway into another world, showing us how even familiar scenes can look much different when photographed over periods measured in seconds.
At night, long exposures produce streaks of light from moving, illuminated subjects like automobiles or amusement park rides.
Extra-long exposures of seemingly pitch-dark subjects can reveal interesting views using light levels barely bright enough to see by.
At any time of day, including daytime (in which case you’ll often need the help of neutral density filters to make the long exposure practical), long exposures can cause moving objects to vanish entirely, because they don’t remain stationary long enough to register in a photograph.
Three Ways to Take Long Exposures
--------------------------------------------
There are actually three common types of lengthy exposures: timed exposures, bulb exposures, and time exposures. The Nikon D3100 offers only the first two. Because of the length of the exposure, all shots with very slow shutter speeds should be taken with a tripod to hold the camera steady.
- Timed exposures.
These are long exposures from 1 second to 30 seconds, measured by the camera itself. To take a picture in this range, simply use Manual or S modes and use the main command dial to set the shutter speed to the length of time you want, choosing from preset speeds of 1.0, 1.3, 1.6, 2.0, 2.5, 3.0, 4.0, 5.0, 6.0, 8.0, 10.0, 13.0, 15.0, 20.0, 25.0, and 30.0 seconds (because the D3100 uses 1/3 stop increments).
- Pros. of timed exposures is that the camera does all the calculating for you. There's no need for a stopwatch. If you review your image on the LCD and decide to try again with the exposure doubled or halved, you can dial in the correct exposure with precision.
- Cons. of timed exposures is that you can't take a photo for longer than 30 seconds.
- Pros. of timed exposures is that the camera does all the calculating for you. There's no need for a stopwatch. If you review your image on the LCD and decide to try again with the exposure doubled or halved, you can dial in the correct exposure with precision.
- Bulb exposures.
This type of exposure is so-called because in the olden days the photographer squeezed and held an air bulb attached to a tube that provided the force necessary to keep the shutter open. Traditionally, a bulb exposure is one that lasts as long as the shutter release button is pressed; when you release the button, the exposure ends.
To make a bulb exposure with the D3100, set the camera on Manual mode, set the f/stop, and then use the main command dial to select the shutter speed immediately after 30 seconds--Bulb. Then, press the shutter to start the exposure, and release it again to close the shutter.
- Time exposures.
This is a setting found on some cameras to produce longer exposures. With cameras that implement this option, the shutter opens when you press the shutter release button, and remains open until you press the button again. With the Nikon D3100, you can't get this exact effect; the best you can do is use a Bulb exposure.
Working with Long Exposures:
------------------------------------
Because the D3100 produces such good images at longer exposures, and there are so many creative things you can do with long-exposure techniques, you'll want to do some experimenting. Get yourself a tripod or another firm support and take some test shots with long exposure noise reduction both enabled and disabled (to see whether you prefer low noise or high detail) and get started. Here are some things to try:
- Make people invisible.
One very cool thing about long exposures is that objects that move rapidly enough won't register at all in a photograph, while the subjects that remain stationary are portrayed in the normal way. That makes it easy to produce people-free landscape photos and architectural photos at night or, even, in full daylight if you use a plain gray neutral-density filter (or two or three) to allow an exposure of at least a few seconds. At ISO 100, f/22, and a pair of ND8 neutral density filters (which each remove three stops' worth of light -- giving you, in effect, the equivalent of ISO 1.5!), you can use exposures of nearly two seconds; overcast days and/or even more neutral-density filtration would work even better if daylight people-vanishing is your goal. They'll have to be walking very briskly and across the field of view (rather than directly toward the camera) for this to work. At night, it's much easier to achieve this effect with the 20- to 30-second exposures that are possible, as you can see in Figures 1 and 2.
Figure 1: This alleyway is thronged with people, as you can see in this
two-second exposure using only the available illumination.
Figure 2: With the camera still on a tripod, a 30-second
exposure rendered the passersby almost invisible.
- Create streaks.
If you aren't shooting for total invisibility, long exposures with the camera on a tripod can produce some interesting streaky effects. Even a single ND8 filter will let you shoot at f/22 and 1/6th second in daylight. Figure 3 shows one kind of effect you can get indoors, without the need for a special filter.
Figure 3: This Korean dancer produced a swirl of color as she
spun during the 1/4th second exposure.
- Produce light trails.
At night, car headlights and taillights and other moving sources of illumination can generate interesting light trails. If the lights aren’t moving, you can make them move by zooming or jiggling the camera during a long exposure. Your camera doesn’t even need to be mounted on a tripod; hand-holding the D3100 for longer exposures adds movement and patterns to your trails. If you’re shooting fireworks, a longer exposure may allow you to combine several bursts into one picture (see Figure 4).
Figure 4: A long exposure allows capturing several bursts of fireworks in one image.
- Blur waterfalls, etc.
You’ll find that waterfalls and other sources of moving liquid produce a special type of long-exposure blur, because the water merges into a fantasy-like veil that looks different at different exposure times, and with different waterfalls. Cascades with turbulent flow produce a rougher look at a given longer exposure than falls that flow smoothly. Although blurred waterfalls have become almost a cliché, there are still plenty of variations for a creative photographer to explore.
- Show total darkness in new ways.
Even on the darkest, moonless nights, there is enough starlight or glow from distant illumination sources to see by, and, if you use a long exposure, there is enough light to take a picture, too.
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