Canon 7D B: Bulb Mode

The Bulb (B) mode on your camera is another manual mode setting that gives you complete control over the shutter speed, but instead of choosing a specifi c setting you are able to leave the shutter open for an indefi nite period of time. The word bulb comes from the early days of photography when camera shutters were pneumatically activated, meaning a bulb was pressed and the air from it was released through a tube that caused the shutter to open and close. It’s a mode that is typically used in dark environments to capture light that is sporadic or changing, such as fi reworks or star trails. It can be extremely useful in creating images that need very long shutter speeds.

When using this mode it’s essential to use both a tripod and a cable release (Figure 3.17). A tripod will keep the camera steady while the shutter is open, and a cable release will open and close the shutter without you having to push the button on the top of the camera, reducing the likelihood of camera shake in your images.

FIGURE 3.17 A tripod and a cable release are essential accessories when photographing in Bulb mode. (Photo by Rich Legg)

WHEN TO USE BULB (B) MODE

When shooting fi reworks displays (Figure 3.18)
When you want to capture trails of lights, such as stars or cars moving down a street at night (Figure 3.19)
When you want to photograph any image in a dark environment at a very small aperture (Figure 3.20)

Using the Bulb mode can bring a lot of creativity into your photography, and there are really no limits to what you can create. The wonderful thing about this mode is that you are able to capture images that are so different from what we see with our eyes. When I lived in the Midwest, I used to chase storms and photograph lightning and was always amazed at the results (Figure 3.21). We see the bolts of light for only a split second, but by using the Bulb mode we can freeze the lightning and see more than we could with our eyes during the storm.

FIGURE 3.18 A long shutter speed was necessary to capture several bursts of fi reworks on one image.

FIGURE 3.19 I left the shutter open for several seconds to catch the trail of lights created by the Ferris wheel as it was spinning.

FIGURE 3.20 A very long exposure was required to photograph this skyline scene at night.

FIGURE 3.21 Although this image was photographed on 35mm fi lm, it’s a good example of the types of images you can create digitally using the Bulb mode on your 7D.

SETTING UP AND SHOOTING IN BULB MODE

Set your camera on a sturdy tripod and attach a cable release to the Remote Control terminal on the side of your camera.
Turn the Mode dial to align the B with the indicator line.
Select your aperture by turning the Main dial.
Select your ISO by pressing the ISO button on the top of the camera and then turning the Main dial (the ISO selection will appear in the top LCD Panel).
Position the camera toward your subject and press the button on the cable release. Hold the button down until you are satisfi ed with your exposure, and then release the shutter.
If you want an extremely long exposure (several minutes or hours), lock the cable release by sliding the button up, which will allow you to lock the shutter in place indefi nitely. The only limitation to your exposure is the amount of life left in your battery.

C1, C2, AND C3: CUSTOM MODES

The Canon 7D comes with three custom modes: C1, C2, and C3. These modes allow the photographer to program specific shooting modes or
exposure settings and save them as a preset. They are extremely useful if you find yourself photographing the same scene again and again and always using the same settings each time.

DIGITAL NOISE AND LONG EXPOSURES

One issue that arises when making extremely long exposures is that you are likely to introduce more digital noise into your images than with a normal exposure. This is one area in which film still has an advantage over digital (Figure 3.22). Digital noise due to long exposures is difficult to prevent, but there are some advanced ways to reduce its effect by using noise-reduction software while editing your images. You can also reduce the amount of noise in-camera by turning on the Long Exposure Noise Reduction setting in your 7D.

FIGURE 3.22 Long exposures photographed with fi lm, such as this image of fi reworks at night, had a high dynamic range (more detail in the darker and brighter areas) and, unlike the digital cameras of today, did not introduce excess noise or grain in the images.