Three Ways to Take Long Exposures
There are actually three common types of lengthy exposures: timed exposures,bulb expo-
sures,andtime exposures. The D7000 offers only the first two, but once you understand
all three, you’ll see why Nikon made the choices it did. Because of the length of the
exposure, all of the following techniques should be used with a tripod to hold the cam-
era steady.
■Timed exposures.These are long exposures from 1 second to 30 seconds, meas-
ured 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, 1.5, 2.0, 3.0, 4.0, 6.0, 8.0, 10.0,
15.0, 20.0, or 30.0 seconds (if you’ve specified 1/2 stop increments for exposure
adjustments), or 1.0, 1.3, 1.6, 2.0, 2.5, 3.2, 4.0, 5.0, 6.0, 8.0, 10.0, 13.0, 15.0,
20.0, 25.0, and 30.0 seconds (if you’re using 1/3 stop increments). The advantage
of timed exposures is that the camera does all the calculating for you. There’s no
need for a stop-watch. 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 pre-
cision. The disadvantage of timed exposures is that you can’t take a photo for longer
than 30 seconds.
■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 D7000, set the camera on
Manual mode and use the main command dial to select the shutter speed imme-
diately after 30 seconds—buLb. Then, press the shutter to start the exposure, and
press it again to close the shutter. If you’d like to simulate a time exposure (described
below), you can use the Nikon MC-DC2 remote control cable or ML-L3 wireless
remote control.
■Time exposures.This is a setting found on some cameras to produce longer expo-
sures. 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 D7000, you can produce this effect with a locking cable release, as I did
for the shot in San Juan, Puerto Rico shown in Figure 7.5. You can press the shut-
ter release button, go off for a few minutes, and come back to close the shutter
(assuming your camera is still there). The disadvantages of this mode are exposures
must be timed manually, and with shorter exposures it’s possible for the vibration
of manually opening and closing the shutter to register in the photo. For longer
exposures, the period of vibration is relatively brief and not usually a problem.
Chapter 7 ■Advanced Techniques 187