Changing Shutter Speed


Your camcorder doesn't have a shutter in the traditional sense. There's no little door that opens and closes quickly to control the amount of light that gets through the lens. However, camcorders can simulate shutter speed by controlling how quickly the CCD sensors refresh the image being recorded, which is measured in times per second. A normal shutter speed is approximately 1/60th of a second, meaning the CCD samples an image 60 times per second.

Why change shutter speed? Using a higher setting is good for capturing fast-moving action like sporting events. The blur caused by moving objects is substantially reduced at speeds of 1/4000 or 1/8000, creating frames that contain very little blurring (Figure 3.5). You'll need to experiment with your camera's settings, though; a high shutter speed can also make the image appear to strobe, or flash artificially.

Figure 3.5. Higher shutter speeds can make fast-moving objects appear clearer.

Automatic

1/2000 shutter speed


Tips

  • Faster shutter speeds require more light. If you think of a traditional shutter, not as much light enters the camera when the shutter is closing more times per second. So a dimly lit room can appear even darker at a high shutter speed.

  • Your camcorder is probably changing shutter speeds without your knowledge. On Auto setting, it detects what kind of light is present, and if it detects fluorescent lightingwhich flickers imperceptibly to our eyes, but can cause havoc on a digital recordingthe shutter speed automatically changes to compensate.





iMovie HD 6 & iDVD 6 for Mac OS X (Visual QuickStart Guide Series)
iMovie HD 6 and iDVD 6 for Mac OS X
ISBN: 0321423275
EAN: 2147483647
Year: 2004
Pages: 197
Authors: Jeff Carlson

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